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Online Painting Cost Calculator (Interiors)

Woman painting a room

Painting a room or a wall is exciting. It’s not terribly expensive, you can do it yourself and the resulting improvement can be dramatic. I love big improvements for little cost and/or effort.

How much will your interior painting project cost you? We created an online painting cost calculator for interior rooms to give you a general idea (we don’t guarantee that it’s perfect). Check it out below.

Online Paint Cost Calculator (Customizable)

Below is our customizable calculator that helps you get an idea as to how much paint and primer you need an then tallying the APPROXIMATE cost you will need to spend on paint. Please see our disclaimer and assumptions below.

=> Hire a local painter here.

How much does it cost to hire professional painters?

Their rates will vary tremendously. They normally charge by the hour. Given the many variables involved such as intricacy of the work, travel time, paint quality, region, etc. we do not include the cost of hiring professional painters in our online paint cost calculator.

Disclaimer: Our calculator ESTIMATES at best. We do not represent or guarantee that your cost will be exactly as calculated because the calculator is based on assumptions which can vary (see assumptions below). Moreover, the calculations are not professional quotes for services. We do not sell nor broker painting services. Our tool is just that… a free online tool to give you a rough idea as to how much you may end up having to spend for your painting project.


There are many assumptions that go into our calculator above. For transparency purposes, those assumptions are listed out in detail below (so you know how the calculations are made):

# of primer/paint gallons needed:

Smooth surface: 1 gallon = 400 sq. ft.
Textured surface: 1 gallon = 250 sq. ft.

Cost of primer:  $18 USD per gallon (obviously this assumption can vary depending on quality and brand).

Cost of paint:

The cost per gallon can vary tremendously. We researched the general paint cost ranges, which are as follows. Yes, you can get cheaper than the stipulated basic and you can spend more than the stipulated best.

  • Basic:  $30 USD/gallon
  • Premium: $50 USD/gallon
  • Best: $85 USD/ gallon


There are many reasons to paint your home, but it can be a daunting process, particularly for big jobs. Some people prefer to just grab a few gallons of paint and jump right in.

I can tell you from experience, this often leads to a last-minute store run in to get more paint. If you don’t have too little paint, you’ll end up with a few gallons stashed in the basement that you are sure you’ll use someday. Years later, the paint cans are still collecting dust.

The other problem with jumping right in is cost. Without using a painting cost estimator, you are guessing at what the total cost of the project will be. This causes its own set of problems.

We’ll look at a painting cost estimator for homeowners who want to do the work themselves, and an estimator for professional painters. Before we get into how to use a paint cost estimator, we’ll look at why you want to use one.

Why Use a Paint Cost Estimator?

A close look at various paint swatches and paint brushes.

There are several reasons to use a paint cost estimator. These reasons include:

  • Selling your home
  • Comparing DIY vs Professional
  • Determining how much to paint
  • Determining what quality paint you can afford
  • Knowing how much paint you need
  • Getting a fair price

Selling Your Home

What does selling your home have to do with a painting estimator? Selling your home is a business venture. Painting the interior and exterior of your home can increase its value. Before you put in the work to repaint, you’ll want to know if it will be profitable.

Generally, painting the interior of your home increases the value by $2,000, and painting the value of the exterior increases by $2,700.

Zillow has found certain colors in specific areas can increase the value even more, but that’s beyond the scope of this article. The bottom line is that paint can increase the value of your home, and knowing how much it would cost you to paint will help you determine if it’s worth it for you.

Comparing DIY vs Professional

We often assume that doing a project ourselves will save money over hiring a professional. This isn’t always true. Professionals have access to discounts on materials, the tools needed to do the job, and they are much more efficient.

If you’d like to learn if you should hire a professional, determine how much it will cost for you to paint your house. Then you can compare it to what it would cost to hire a professional. Don’t forget to include your time and convenience when considering the difference in price.

Determining How Much to Paint

Maybe you plan to paint the entire interior of your home, only to learn that you can’t afford it. You can use the cost estimator to determine how much of your home you can afford to paint.

If it’s the interior, you may paint a room or two. If it’s the exterior, paint the trim and the front door. Painting doesn’t have to be an all-or-nothing venture.

Determining Quality of Paint

Another way to adjust the cost of your paint job is to choose a more affordable paint. Generally, higher quality paint will cost more than lower-quality options.

If it’s in the budget, you can choose a higher quality paint at greater expense. If money’s tight, choose an economical paint. All interior and exterior paints today meet basic quality standards, and it is possible to get a great finish with relatively inexpensive paint.

Determining How Much Paint You Need

If you are doing the painting yourself, you’ll need to know how much paint you’ll need. This is part of the process of estimating the cost of painting. Too much or too little paint causes unnecessary expense or inconvenience. This can easily be avoided by estimating how much paint the project requires before you purchase your materials.

You Want a Fair Price

Maybe you know you want to hire a professional painter. You have two choices. You can get an estimate and assume it’s a fair price. Or you can use a paint cost estimator to get an idea of what a fair price would be. You’ll then know if you should speak to another painter, attempt to negotiate or accept the estimate as given.

Types of Paint

A close look at cans of various paints.

Before we get into the costs, we’ll take a quick look at the paint. There are a few basic types of paint.

These are:

  • Oil-based paint
  • Latex paint
  • Hybrid paint
  • Primer

Oil Based Paint

Oil-based paint used to be the gold standard for wall paint. However, as latex paint has improved, it can be a better option. Many professionals still prefer oil-based paint, because it provides a smooth surface without showing brushstrokes.

However, it has a higher VOC, which are fumes that can be dangerous to breathe in an enclosed area. It’s also harder to clean up and takes longer to dry than latex paint.

Oil-based paint is great for high moisture areas like bathrooms. It’s also good for high-traffic areas. It’s sometimes used for cabinets, doors, and kitchens. Oil-based paint is often used as an exterior paint for siding or wood. It’s generally more durable than latex paint and dries to a hard shell.

Latex Paint

Latex Paint being poured onto a plastic tray with a roller.

Latex paint can now compete with oil-based paint. It can prevent mildew and moisture. It provides good coverage. Today’s latex paint can even compete with oil-based paint in terms of durability, and some can be used for exterior painting.

Latex paint is easier to clean up because it only requires soap and water. It also dries faster than oil-based.


Hybrid paint combines the application and look of oil with the easy clean up of latex. It’s durable like oil and great for exterior paint, and faster drying like latex.


Primers are also oil or latex-based. Oil-based primers are the best for stain coverage. If you want to cover moisture stains, have softwood that might bleed through, it’s a good choice. Oil-based primers have the same disadvantages as oil-based paint.

Latex primer is great for drywall because it evens out imperfections. It has some stain blocking abilities and is easier to clean up just like latex paint.

Paint finishes

A modern white bedroom with a glossy white finish on the wall behind the headboard.

Paint finishes are another consideration. Regardless of choosing latex or oil-based paint, you’ll need to determine the finish you want.

Paint finishes include:

  • Flat: Hides imperfections, absorbs dirt and stains
  • Satin/eggshell: low gloss provides slight sheen, easier to clean
  • Semi-gloss: Medium gloss provides significant shine, easy to clean, shows imperfections
  • High gloss: ideal for trim, the high shine is too much for walls

Professional House Painting General Estimate

A professional house painter spray painting the balcony railings.

Before we discuss using a paint cost estimator, we’ll take a quick look at some average numbers. These are only to give you an idea of what your painting project will cost, not an estimate.

Costs for interior painting range from $1.50 to $3.50 per sq ft. If you need ceilings and trim painting, $3 to $4 per sq ft.

On average, a one-room painting job will cost $350 to $800. To paint the full interior will cost $1,200 to $3,900.

Costs for exterior painting range from $1,715 to $3,676 for most jobs, with the average painting project costing $2,500.

Paint Cost Estimator for Homeowners

This is an image representation of a painting cost calculator.

A paint cost estimator for homeowners is relatively simple. The key is to determine how much paint you’ll need. Other materials will also be included, particularly for exterior paint. This is also the first step to a professional paint estimator.

Interior Paint Calculator

1 gallon of paint will cover 400 sq ft. You’ll need to know the size of the area you want to paint in sq ft. To accurately determine how much paint you’ll need, you should measure each wall.

You’ll multiply the length of each wall by the height. Then add the numbers together.

If a room has four walls that are 12 ft long and 10ft tall each, you’ll multiple 10×12. This equals 120. Repeat the process for each wall, and you get 120+120+120+120. This equals 480 sq ft.

You can also use this calculation:

(LxH) +(LxH) + (LxH)+ (LxH) = total wall area

If you want to skip the math, you can use the Glidden paint calculator. You’ll just need the width and height for each wall in the room. You can also use the DutchBoy Interior Painting Calculator. Just put in the width, length, and height of your room.

Both also factor in windows and doors for a more accurate estimate and tell you how much paint you need.

If you are doing your own math, just remember one gallon covers 300-400 sq ft. A room between 400-800 sq ft will need two gallons of paint. These calculations assume that you are using one coat of paint. If you are using two coats of paint, you’ll need to multiply the total square footage by two.

Exterior Paint Estimator

A close look at a woman applying protective varnish to the exterior walls of the house.

Estimating exterior paint is similar to estimating interior paint. You can use the Dutchboy Exterior Paint calculator. In addition to doors and windows, you can select a rough or smooth texture. A surface with a rough texture will require more paint than a smooth texture.

Calculating Paint Costs

When it comes to calculating paint costs, first you’ll need to decide the cost of the paint. Paint for homeowners usually costs between $30-60 dollars per gallon.

Multiply the cost of the paint by the number of gallons you need to determine your materials cost.

Professional Painter Paint Cost Estimator

A couple of men looking at swatches of paint samples.

Knowing how to calculate the amount of paint needed is a good first step, but there are several other steps involved in a professional paint cost estimator.

Simple Cost Estimator for Interior

If you’d like an idea of how much it would cost to paint the entire interior of your home, you can use the Paint Cost Estimator from

You’ll enter the total square footage of your home, the number of doors and windows, and the number of stories the home is. You’ll also select from new construction or painting an existing home. You’ll select whether you want ceilings painted and your area.

The calculator will give you an estimate for what a professional would charge in your area.

What’s in a Price?

Materials are often the focus of cost calculations. Professional painters can purchase paint and other materials wholesale, which allows them to pay approximately half of what a homeowner would pay. In fact, labor accounts for 75-80% of the total cost.

Estimating the Cost Manually

A man computing his painting costs.

If you are a professional painter, estimating manually gives you the flexibility to set your own price for labor and other factors. If you are a homeowner, it gives you a better idea of the individual costs involved. When you receive an estimate, ask the painter to break it down based on these factors.

You’ll start with the amount of paint you need based on the square footage of the area to be painted. You’ll determine how much the paint will cost, based on the average or the particular paint you choose.

Calculating Labor

Calculating labor is more complicated. The average is $20-60 an hour, but this varies widely based on where you live and the painter’s experience level.

If you are figuring out what to charge for a job, you’ll need to decide how much you want to pay yourself and any employees per hour.

It can also be difficult to determine how many hours it will take to complete a job. Many factors, which we’ll get into soon, can affect the time, and the expense, of completing the job. On average, it takes 2 painters 1-2 days to paint a 2,500 sq ft home interior.

Estimating time and labor is a bit of an art. A skilled painter will be able to look at a home and get a better estimate of the labor involved than someone who is inexperienced. A rough estimate is 150 sq ft per hour of labor.

Factor in Marketing and Overhead

You should also factor in costs of marketing and overhead. This includes advertising costs and office overhead. Generally, this is 10% of the cost of the materials and labor.

Decide Your Markup

Your markup should be at least 30-50%. To determine the percentage, you’ll need the total cost of doing the job.

This can be found by using the formula:

Materials+labor+overhead=project cost.

Next, you’ll use the formula:

Project cost x (the percentage you choose for markup)=markup

This is your profit margin. After all the expenses associated with completing the job, this is the amount you should clear for profit.

Consumer Project Cost

A close look at a contractor doing an estimate on the house.

The initial project cost is what it costs you to do complete the project. To determine the consumer project cost, you’ll follow this formula.

Initial project cost + markup = consumer project cost.

Determining Price Per Square Foot

Most contractors charge by the sq ft instead of an hourly rate. To determine the price per square foot, you’ll take the total price of the job and divide it by the total square footage.

Average prices range from $2-6 per square foot.

Costs of Hiring a Professional Painter vs DIY

A father and son painting the interior wall of their house.

If you want to determine the cost of doing the job yourself vs hiring a professional, you can use a similar calculation.

Start with your square footage. Determine how many cans of paint you’ll need and the price per gallon.

Gallons x price per gallon= materials cost.

Next, you’ll determine how long it will take you to complete the job. If you are inexperienced, you will move at a slower pace than a professional. It’s a good idea to estimate 80-100 sq ft. per hour.

Total sq. ft / sq ft per hour= total labor time

Now, decide how much your time is worth. You can consider what you would be paid at your own job, or how valuable it is based on other things you could be doing.

Total labor time x price per hour= labor costs

Now it’s time to figure out how much it will cost you to do the project yourself.

Materials cost + labor costs= total cost

This is what it will cost you in terms of time and money to complete the project yourself. How does it compare to the professional estimate?

Would you really save a significant amount of money doing it yourself? Is it worth the extra expense to hire a professional?

Should You Use a Paid Estimator? 

A man stressing about the cost of painting the house.

There are several ways to estimate a paint job. You can use a free paint cost estimator, like the ones listed earlier, or you can make the calculations yourself.

The other option is to use a paid painting cost estimator. These can be useful, particularly if you are busy or just starting out.

1build is a great example. It combines real professionals with decades of experience with AI algorithms. It also takes prices in your local area into consideration.

STACK is an app that allows you to create estimates, invoices, and collaborate with members of your team. You can easily adjust values for categories, including markup and taxes, and save all your documents. It’s perfect for a professional look if you are a small painting company.

For a cloud-based painting cost estimator, check out PEP. It’s an easy-to-use estimator that allows you to create professional virtual bids and presentations. Presentation is key to success, and PEP gets the job done.

Cost Considerations

A close look at a worker painting the exterior walls of the house.

A painting cost estimator is a good start, but many factors will affect the estimate and cost. We’ll look at these key factors.

Factors include:

  • Primer
  • Coats of paint
  • Ceiling
  • Windows and trim
  • New vs. Existing construction
  • Repairs
  • Painting materials


A close look at a man applying primer paint on the interior wall.

Paint isn’t the only thing you need to factor into your material cost. In many cases, you’ll need a primer as well. Many paints have built-in primer, but this differs vastly from using a primer.

You can expect one gallon of primer to cover 200-275 sq ft. You will need one to two coats of primer. Primer is usually less expensive than paint, at an average of $50 for a 5-gallon bucket of primer.

When determining material cost, you’ll determine the primer cost the same way you determine paint cost. Just use the appropriate numbers and add the cost of primer and paint together for your cost estimate.

You should always use a primer if you are:

  • Painting new construction
  • Painting over repairs
  • Attempting to cover stains on a previously painted wall
  • Painting with color more than a few shades different, particularly a lighter color than the existing color

Coats of Paint

Most painting jobs require two coats of paint. Depending on the quality of the paint and whether primer was used, one might be acceptable. If the paint is satin, semi-gloss, or full-gloss, two coats may be required to get a smooth finish.


A close look at a ceiling being painted with a roller.

Does the ceiling need to be painted as well? You’ll need ceiling paint for the ceiling, so you’ll need to factor that in as well.

The ceiling area can be calculated by multiplying the width and length of the walls.

Length x Width= Ceiling area

Ceiling paint costs around $30 a gallon for medium quality paint. Painting a ceiling is more work than painting walls, so labor costs will be higher. If you have a vaulted or cathedral ceiling, you’ll probably pay 50% more to get your ceiling painted.

Windows, Doors, and Trim

A close look at a window frame that is painted white.

Windows will take away from the surface area to be painted. If you aren’t painting doors, you can remove their area as well. An average window is 15 sq ft, and a door is 21 sq ft.

If you are doing manual calculations, here’s the formula.

Total surface area – total door and window area = area to be painted

If you plan to paint the trim, you’ll need to calculate that as well. You’ll need the perimeter of the room, which is the length of all four walls. You can subtract 3 ft for each door from this.

Then, you’ll multiply the perimeter by the width of your trim.

Perimeter x trim width = trim area

If you plan to paint the windows, doors, and trim a different color than the walls, you’ll use this calculation.

Total door and window area + trim area = accent paint area


An electric wire hole being repaired with wall putty.

If your home requires repairs, this will add to the cost as well. It requires more labor, and materials, which will get to next. How much cost repairs add will depend on how extensive they are.

Prep work should also be considered. If existing paint must be removed, which often happens with exterior painting, this adds to the labor costs. With interior painting, areas will need to be covered with masking tape and a drop cloth will need to be laid.


So far, we’ve looked at paint and primer. If you’ve ever painted a room, you know other materials are required as well.

These materials and associated costs vary based on the job. For an exterior painting with a 2,500 sq ft home, you can expect:

  • Masking Plastic (2 rolls) $25
  • Masking Paper (3 rolls) $15
  • Tape (10 rolls) $35
  • Caulking (6 tubes) $15

These specific materials needed will vary from interior to exterior, but on average you can expect materials to cost $100-$150.

Other Cost Factors

A close look at a man painting the wall with a roller.

To further complicate a painting estimate, there are a few other factors that affect the price of a painting job.

Costs for Interior vs Exterior

When getting a painting estimate, interior painting is usually cheaper than exterior painting. This will depend on the prep work involved and the exterior painting surface. As a general rule, the exterior can cost 25% more than interior painting.

Small Vs. Large Projects

Small projects will cost more percentage-wise than larger projects. Any project requires a certain amount of paint, materials, and time. A professional painter will need to recoup these costs.

A larger job will cost a higher total amount because the total square footage is higher. But most professionals will have a higher markup in smaller jobs.

Painting Cost Estimator FAQs

How much do painting costs change from state or area?

Painting costs can vary significantly based on where you live due to a few factors. The first is the cost of living and affluence of the area. If it costs more to live in the area, labor will be more expensive.

Weather is another factor in house painting. Areas with high humidity or frequent rain may require higher quality paint, which will cost more.

The price of the painting job can also be affected by the cost of materials in your local area. If material costs are higher for the painter, these costs will be passed on to the consumer.

How much should you pay a painter upfront?

Painters usually require 20-30% of the total cost upfront. You should never pay for the entire job upfront, in case of problems arise. The amount paid upfront helps cover material and some labor costs, which helps the painter avoid paying a lot out of pocket. It also motivates them to get the job done correctly.

How much should you tip a professional painter?

There’s no expectation of tipping for a paint job. However, it’s not unheard of. $10-$20 per painter is the norm if you are very pleased with their work.

If the job was high-end, consider tipping more. However, the biggest tip you can give doesn’t cost anything. Leave a positive review of their business online.

Which is better, using a sprayer or rolling on paint?

This really depends on what and where you are painting. Sprayers use 33% more paint than roller and paint trays. Sprayers have a quicker application, but more prep work.

Spraying paint is usually better for ceiling paint with popcorn or textured ceiling, siding, and brick. If the area is hard to reach or textured, spraying is probably the way to go.

For wall painting, rolling paint is usually the better option. However, if there are very large wall areas like those often found in commercial painting, spraying can be an economical choice. It’s a question of prep work vs. painting time.

Should you paint walls or trim first?

A professional painter will usually paint the trim first. They will paint the ceiling, and then the walls. This is because it’s faster to tape the trim and ceiling than the walls.

Can you paint over old paint?

The short answer is yes. The longer answer is it depends. If the colors are similar and the surface is in good condition, you should be able to paint directly over the old paint.

Drastic changes, especially dark to light or light to dark, will require a few coats of primer before you paint. You’ll also need to know which type of paint you are painting over.

Oil-based paint will not stick to latex paint, so you’ll need a primer. To determine which type of paint you currently have, look at a paint chip. If it’s flexible, it’s latex. If it’s brittle, it’s oil-based.

Can you use interior paint for exterior painting?

In short, it’s a bad idea. If you’ve gotten an exterior painting estimate, you may have noticed that exterior paint is more expensive. It contains resins and additives to help it withstand weather conditions.

Interior paint is designed to look good and wash easily. Exterior paint is designed to withstand moisture, sunlight, and temperature changes. Interior paint simply won’t last if applied to the outside of your home.

Can you use exterior paint for interior painting?

Moisture and mold resistance might be just what you need for certain areas of your home, so can you use exterior paint inside? It can be a good choice for bathrooms and basements. Just be aware that most exterior paints have a higher VOC, so proper ventilation is important.

Can you get paint out of clothes?

You excitedly jump into your painting project and then remember you are wearing a favorite shirt. Are you out of luck?

If it’s latex paint, you can apply dishwashing liquid directly to the stain. Let it sit for at least 30 minutes, and then wash. You can also try using alcohol in the same way.

Oil-based paints are more difficult. Try applying turpentine to the stain. Let it sit for a few minutes, dab with a clean towel, and rinse. Repeat the process until the paint is removed.