How to Estimate Your Next Paint Job Like a Pro

A new contractor often assumes that preparing the painting estimate for a project will be the least of his worries. It’s simple right? Do some basic math and quickly figure out how much paint it’s going to take to cover a given surface. A contractor’s far more concerned about developing an accurate estimate for the total labor and equipment, which are so difficult to control and more likely to eat into his project margins. But underestimating the difficulty in preparing a painting estimate could be a mistake. 

It is one thing to know how much paint it will take to cover a surface and quite another to know how long it will take to cover that surface. Imagine the surface you’re painting isn’t a standard 10 x 12 interior room and has more window than surface area and a vaulted ceiling. Now imagine it includes reclaimed walls or non-standard surfaces. What simple math calculation will help you estimate how many coats you’d need? Or how much paint would it take to cover that surface? More importantly, how difficult would it be to figure out exactly how long it will take to paint that non-standard interior room?   

While other industries such as auto repair are able to prepare accurate estimates because their work is always standardized and produced in controlled conditions such as a repair shop, the opposite is true for painting jobs. There are simply too many variables. For example, no 4-bedroom house built in 2005 is the same and the work is always completed onsite, which makes every paint job a custom job. No single painting estimate will ever cover all cases, but that doesn’t mean an accurate estimate is impossible. It simply means you need to review and thoroughly understand the variables that go into each painting estimate or you should outsource your estimate to a construction cost estimating service.

Because painting estimates are always custom estimates with many variables, we’ve developed a step-by-step guide for new and experienced contractors on how to prepare an accurate painting estimate for any job, which will save you time, help you win more bids, and increase your margins. 

Here are the seven steps for  how to estimate a paint job:

1. Step 1: Review the Plans
2. Step 2: Complete Painting Checklist Estimate
3. Step 3: Estimate the Cost of Materials
4. Step 4: Estimate Cost of Labor
5. Step 5: Estimate Cost of Overhead and Marketing 
6. Step 6: Determine Your Markup
7. Step 7: Determine Final Painting Estimate

Step 1: Review the Plans 

While it’s always a good idea to visit a jobsite before completing a painting estimate, you can save time and money by thoroughly reviewing the project plans or the specifications of the structure you need to paint. The more knowledge you have of the structure and the surface area you need to cover, the more likely it is that your job will be successful. It’s especially important for painting contractors involved in new construction or renovation projects. Unfortunately, many contractors are not nearly as proficient at reading plans as they should be. 

There are many points in the design phase where errors can be introduced in plans and even small mistakes can end up costing a painting contractor’s profit. So you’ll want to examine the plans to ensure there are no errors and that the measurements are clear and readable. 

Review all of the following for interior paint jobs:

• Site Plans
• Floor Plans
• Interior Elevations Drawings 
• Reflected Ceiling Plans
• Various schedules the architect has provided

Once you’ve studied the plans and truly understand the project, you’re ready for the next step, which is to complete a Painting Estimate Checklist.

Step 2: Complete Painting Estimate Checklist

As you’re now thoroughly familiar with the site plans, here are some standard variables you will want to watch for. Use these questions as the basis for a basic checklist you complete before estimating any painting job. 

Checklist of Questions to Answer for Estimating a Paint Job:

General questions:

• How experienced is the painting team (pro or novice)?
• What brand of paint will be used? (known or unknown/client supplied)?
• How exacting is the customer (lax or fastidious)?

Conditions and preparations:

• Are the surfaces flat, or do they have raised molding or louvers?
• Will any panels require repair or replacement?
• Are panels real wood, metal, or plastic?
• Are there hard-to-remove imperfections (scuff marks etc)
• Is the surface smooth or will it need filler and sanding?
• Do the screws, nails, and glue joints for doors and windows need repair?
• Are the door bottoms clear of the floor or rub on carpets?
• How many coats of prior finish are on the surfaces? 1, 3, or 12?
• Was the last coat of finish properly applied to the surfaces or does it need to be stripped?
• Do any of the surfaces need to be washed, scrubbed, or cleaned with chemicals?

Hardware

• Will the hardware on the site be easily removed (doorknobs? hinges?)
• Will the hardware finish need to be replaced or refinished?
• Are any hinges clean and free-swinging?

Painting

• Will the surfaces be painted or stained? 
• Will the surfaces be painted in latex, enamel, lacquer, or polyurethane?
• Will all sides of the surface be the same color? Will any sides of the surface require more than one color? 
• What tools will you use to cover the surfaces (brush, roller, spray)?
• If multiple coats, how much drying time between coats?
• Will you have to make a second or third trip to complete the job?

As you can see, depending on how you answer these questions, the time it takes to complete a job can vary dramatically, no matter how experienced you are. And it highlights again, that for the most part, every painting estimate is a custom job. For these reasons, you should work through this checklist or one similar that you customize for each job before you develop the estimate. 

Step 3: Estimate the Cost of  Materials

Once you’ve completed your painting estimate checklist, it’s now time to estimate the cost of materials, which include paint and supplies. 

What is the Cost of Paint?

When it comes to the price of paint per gallon, a wide range exists--anywhere from  $15 - $80 dollars, depending on the brand and the quality. But in general, paint per gallon will cost you roughly $15 to $50 dollars on average. A veteran contractor with established relationships with vendors can purchase paint for half the price of a client or owner. For example, if a homeowner can purchase a gallon of paint at $40, an experienced contractor can purchase it for $20. As you become more experienced, leverage your relationships with vendors to save money by receiving bulk discounts for paint.

Here we break down the cost of paint for an owner versus a contractor for low, medium, and high-quality paint. Again, these are just general estimates as the price could be lower and in some cases for specialty paint even higher. 

The Cost of Paint Per Gallon

Obviously, high-quality paint costs more but to know what quality paint is you need to be familiar with the types of paints and what they are used for. To complete any painting estimate every contractor needs to select the paint “type” and then choose a “finish.” 

Although there are 5 types of interior paint--latex and oil-based paints, epoxy, urethane, enamel, stain, and lacquer--the two most commonly used for interior paint jobs are latex and oil-based. Latex paints, which dry quickly and are long-lasting, are commonly used on walls and ceilings whereas oil-based paints, which are more durable and take longer to dry, are traditionally used on the trim. 

Each type of paint has a different drying time. Latex paint can dry to the touch within 30 minutes whereas urethane often takes over an hour and in some cases needs five days to dry completely. And all drying times depend on the following factors: brand, coat thickness, humidity, and how porous the surface is. 

Beyond paint type, every paint has a specific finish and there are again typically 5 finishes of paint: 

1. Flat
2. Eggshell
3. Satin 
4. Semi-gloss
5. High gloss 

Flat finishes are typically the cheapest and high gloss is the most expensive. Moreover, the cost goes up about 1 dollar on average per finish style. So if 1 gallon of flat paint costs $20, 1 gallon of eggshell would be $21 and 1 gallon of high gloss would be $24.  

The Cost of Interior Paint

But to estimate your total cost, you’d need to know how much paint for the entire project? To calculate the cost of paint for the complete structure you’ll need to complete a simple calculation to determine paint cost:

 total gallons of paint x price per gallon = paint cost 

If for example, you need 10 gallons of paint to complete the job and paint is roughly $30/gallon your total paint cost would be 10 x 30.00 = $300. 

But how do you determine how many gallons of paint? A gallon of paint typically covers 250 to 400 sq ft of surface area. So, to determine how many gallons, you’ll need to first:

How to determine the square footage of a room for painting:

1. Measure the total distance or perimeter around the (10 ft. x 15 ft.) room: 
2. (Length + Width) x 2 = Perimeter
3. (10 ft. + 15 ft.) x 2 = 50 ft.
4. Then multiply that number by the ceiling height to get the total wall area: 
5. Perimeter x H = Total Wall Area
6. 50 ft. x 8 ft. = 400 sq.ft. 
7. Then you’ll need to subtract any surface you’re not painting, such as windows and doors. Windows typically average 15 sq.ft. and doors 21 sq.ft. In our example, there are two windows and doors:
8. Doors: 21 sq.ft. x 2 = 42 sq.ft
9. Windows: 15 sq.ft. x 2 = 30 sq.ft. 
10. Total Wall Area - Minus Doors - Windows = Total Wall Coverage
11. 400 sq. ft. (wall area) - 42 sq. ft. (doors) - 30 sq. ft. (windows) = 328 sq. ft. 
12. Next, calculate the paint needed for the ceiling using this simple formula
13. Length x Width = Ceiling 
14. 10 ft. x 15 ft. = 150 sq. ft.
15. Finally determine the paint needed for the doors, windows and trim using the calculations above for doors (42 sq. ft.) and windows (30 sq. ft.) and this basic baseboard calculation:
16. Perimeter - Door Length (3 ft x 2) = Baseboard Coverage
17. 50 ft. - 6 ft. = 44 ft.
18. Multiply it by average trim width (.5 ft) 
19. then 44 ft. x .5 = 22 sq. ft. 
20. Add the coverage for the walls, ceiling and trim together to arrive at total room coverage:
21. Wall Coverage + Ceiling Coverage + Trim Coverage = Total Room Coverage
22. 400 sq. ft. + 150 sq. ft. + 92 sq. ft. = 642 sq. ft. 

If it’s too complicated to factor in trim paint into your calculation, a good rule of thumb to follow is that there is generally a  4:1 ratio for paint for body vs. trim. So as an example, if you need 20 gallons of body paint, you’d need 5 gallons of door/window/ trim paint. 

Your paint job estimating coverage might be done here depending on the job. More than likely, you’ll want to run the same calculations for each room in the structure you’re painting and add those together to determine your total coverage in square feet.   

Now that you know how much coverage you’d need, you’re finally ready to determine the basic paint cost per square foot. 

Basic Paint Costs Per Square Foot

1 gallon of paint will cover approximately 400 sq feet. 

Cost of Supplies

Beyond paint, you will need to factor in the cost of other supplies to apply the paint. Here is a list of common supplies that need to be factored into your cost estimate for materials for a project that is roughly 2500 sq ft: 

• Masking plastic: 2 rolls
• Masking paper: 3 rolls
• Paint tape: 10 rolls
• Caulking: 6 tubes
• Tarps: 10+
• Brushes, rollers etc
• And primer: 1 gallon

Prices of these vary depending on the brand and the geographic location, but generally between $120 - $150.  

Step 4: Estimate Cost of Labor

Once you know how much your materials will cost, it’s time to estimate the cost of labor. Unfortunately, there is simply no easy way to estimate labor for painting due to the extreme quantity of variables of every painting job. While there are some basic general numbers you can use to estimate, these numbers could actually be very low depending on certain variables and could cost you money. According to experts, painting labor is typically estimated at 20/hr per person. But how many painters will you need and for how long depends again largely on the unique conditions of the job. Typically, it only takes one to two days for two experienced painters to paint a 2500 sq. ft. home and costs usually approximately $600-$800 a day.

While it is tempting to use basic estimates for standard square footage, as noted earlier, all of the following could double, triple or even quadruple your labor costs: excessive repairs, excessive prep work, cleaning or treatment, poor quality paint, non-standard size surface areas, difficult surfaces areas, special customers design or paint requests. 

So again, your best course of action is to complete the Painting Estimate Checklist so you can accurately estimate labor. 

Step 5: Estimate Cost of Overhead and Marketing 

It’s a good idea to include the cost it takes you to run your business and to market it to ensure you’re not actually losing money on your projects. While everything we’ve included in this guide helps you estimate the costs of the actual project, you shouldn’t forget what it costs to do business or to find new business. While you may charge 5k for a larger painting job, you’re only making 3k if it costs you 2k in advertising costs to find the client and get his business. Not factoring in these costs is how your profit margins begin to slip. To ensure they don’t, try to make sure it’s costing you no more than 10% of the job price to get the job. 

Step 6: Determine Your Markup

Next, you want to ensure that you factor in your markup into your final estimate. To learn what markup is and how and why factoring markup is important, read our guide on how to increase your construction profit margins. While each contractor business is unique and size affects how much markup each company should charge, you should be aiming for no less than 50% of profit margin if you’re a small contractor and approximately 30% if you’re a larger company. This markup not only ensures you’ll make a profit, but also that your business will continue to grow. It also helps you account for all of the variable or hidden costs that were impossible to anticipate when you initially started, including mistakes or oversights.  

Step 7: Determine Final Painting Estimate

The final step is to calculate your final painting estimate with this formula:

Materials Cost + Labor Costs + Overhead/Marketing Costs + Markup Costs = Total Painting Project Costs

While not explicitly called out, you should also factor in some cushion for mistakes or issues you failed to catch during the estimating process.  

And finally, for help creating the final estimate and submitting a winning bid, check out our comprehensive construction bidding guide.           

Eliminate Estimating Headaches and Get Your Painting Estimate Right Every Time

Save money and win more bids by outsourcing your next painting estimate to cost estimating services. 1build is an enhanced cost estimating service that combines the experience of real estimators with the accuracy and detail of AI to help you create more accurate estimates. Leverage the power of human estimators with over 20 years of field experience developing estimates. Simply subscribe, upload your plans, and get detailed and accurate painting estimates within days.

Sign up for 1build online today to learn more and see it in action.