Painting your home can give it a fresh new look, but how much will it cost? Here’s what you might pay for interior and exterior paint projects.
How Much Paint Do I Need For My Project?
This simple equation will help you calculate exactly how much paint you need
Photo: svetikd / E+ / Getty Images
Photo: svetikd / E+ / Getty Images
Highlights
A gallon of paint can cover about 400 square feet of wall space.
Multiply the length and height of each wall and add them together to find square footage.
Subtract the area of windows and doors.
Add about 15% to account for overage.
Painting a 300-square-foot room will take a gallon and a half of paint for two coats.
Get quotes from up to 3 pros!
Enter a zip below and get matched to top-rated pros near you.
Painting your home can transform it from drab to fab in just a few strokes. But somewhere along the way, you’ll probably ask yourself, “How much paint do I need?” With a little bit of simple math, you can figure out exactly what you need and avoid having to throw away leftover paint.
How Much Paint Do I Need for Different Rooms
A gallon of paint covers around 400 square feet, while primer covers 200 to 300 square feet. If you’re painting a single room, you may only need one gallon of paint. However, if you need to use primer, do multiple coats, or paint an entire floor of your home, your paint needs will increase.
| Room Type | Wall Square Footage | Amount of Paint (1 coat) | Amount of Paint (2 coats) |
|---|---|---|---|
| Bathroom | 200 | ½ gallon | 1 gallon |
| Kitchen | 400 | 1 gallon | 2 gallons |
| Bedroom | 450 | 1 ½ gallons | 2 gallons |
| Living room | 800 | 2 gallons | 4 gallons |
| Open-plan living space | 1,600 | 4 gallons | 8 gallons |
Calculating How Much Paint You Need
To figure out how much paint you need for your project, you’ll need to calculate the square footage of the walls that need to be painted (more on that below). Once you have that figure, the following formula can help you determine how much paint you need:
Wall square footage - door and window square footage x 10% to 15% wastage = total paintable wall space
Once you have the total paintable square foot, apply the following formula:
Square footage / 400 = gallons of paint needed
How to Measure a Room for Painting
Before you head to the paint store, you should calculate how much paint you need. A gallon of paint costs between $20 and $70, so buying more than you need can waste quite a bit of money. Knowing that a gallon of paint covers around 400 square feet, you can determine how much you’ll need by calculating the total square footage of the walls to be painted.
Calculating Paint Needed for a Room
To determine how much paint you need in a basic room, you’ll need to calculate the room’s square footage by taking the following steps.
Measure the lengths of each wall from corner to corner.
Measure the height of each wall from floor to ceiling.
Multiply the length of each wall by the height to get the square footage.
Add the square footage of each wall together to get the total square footage of the room.
Subtract the size of any windows and doors in the room.
Multiply the total square footage by 0.10 or 0.15 to account for wastage.
Divide the total number by 400 to calculate the gallons of paint you need.
For example, a room with 400 square feet of paintable walls would require one gallon of paint for one coat or two gallons of paint for two coats. You may be able to stick with one coat if you’re painting over a similar color, but it’s often best to plan for two coats to avoid any streaks.
Calculating Door and Window Size
If there are doors and windows in the room you want to paint, you’ll need to calculate their size and subtract that number from the room’s square footage. Here’s how to do that.
Measure the door or window area, including the frame and glass
Add the area of all doors and windows together
Subtract that number from the wall square footage
For example, a room that has 400 square feet of wall space and 50 square feet of window and doors will have a total paintable area of 350 square feet, requiring just under one gallon of paint (or two if you want to do a second coat).
Calculating Paint Needed for Ceilings
If you want to paint the ceiling, you’ll need to measure it as well. To do so, take the following steps:
Measure the ceiling’s length and width
Multiply the numbers to calculate the total square footage
If you want to paint the ceiling the same color as the walls, add the ceiling square footage to the wall square footage
For example, a 10-foot-by-12-foot ceiling measures 120 square feet. Adding that to our 350-square-foot wall brings the total paintable area to 470 square feet, or just over one gallon of paint for one coat or around 2.35 gallons for two coats.
Who to Hire to Paint Your Home
Painting your home as a DIY project can save you money on labor. However, it’s a time-consuming and physically demanding project. If you prefer to leave painting to the pros, you can hire a local interior painter to paint your home for you. A pro will know how many coats are needed based on your home size and can often get discounts on supplies from local paint stores. Expect to pay around $400 to $1,600 for the cost to paint a room using a pro.
Frequently Asked Questions
The homeowners guide to interior painting services
From average costs to expert advice, get all the answers you need to get your job done.
How much does it cost to paint a room? Learn what you’ll pay to give your space a makeover, depending on room size, paint type, the pro you hire, and more.
The cost to remove texture from walls depends on square footage and the type of texture. Learn all the factors that will impact your budget in this guide.
Learning how to do a knockdown texture yourself can be a challenging, messy process. Learn the steps required, then decide whether to DIY or hire a pro.
No one wants a bathroom with peeling paint and mold buildup. Picking the best paint for bathrooms helps you steer clear of these shower room setbacks.
Matching the perfect paint sheen to the project you’re doing is easier when you understand the differences in eggshell versus matte paint finishes.