How Much Paint Do I Need?

No more guessing – find out how much paint you’ll need for that project, before you buy. (With free printable worksheet!)

I’ve written a lot of articles about DIY painting projects (cabinets, furniture, doors, rooms), and the number one most frequent question I get is…

How much paint do I need?

Whether it’s a wall, a kitchen full of cabinets, or a piece of furniture, deciding how much paint you’ll need is one of the first steps in planning your project.

While it may seem like an afterthought until you’re standing at the customer service desk of your favorite paint store, purchasing the right amount of paint before you start a project is actually super important. You don’t want to be scrambling to finish a project with paint that you *think* is the same as what you started with.

Trust me, I have learned this the hard way.

I once was making over a whole house, and realized somewhere along the way that when we had gone back to the hardware store for more paint to finish the last room, we accidentally got semi-gloss instead of flat. So halfway through the living room, the walls morphed from flat paint into glossy. There was no way to not see it so we had to redo it all over again.

And don’t even get me started on mixing colors! Every time you blend a new gallon of paint, you run the risk of the color being slightly different. While this is rare with computerized color mixing, it’s not a risk I want to take when I’m doing an intense painting project, like kitchen cabinets.

When I painted my kitchen cabinets, I used a custom color that I mixed myself. In that case, I had to make extra sure that I had plenty of paint for the whole project (as well as leftovers for touch ups later) because I knew there was no way I could re-create that exact same color mix again.

This is when you need to know how far your paint will go before you make the purchase or mix the paint. Fortunately, you can figure this out on your own, with a few basic pieces of information. And maybe a calculator.

The square footage of your project is a little harder to find, but don’t worry! I’ve created a simple worksheet to guide you through the calculations. Let’s look at how to use the worksheet, and then how to download your own.

Here’s mine, with the notes for painting a room:

Paint Worksheet Step 1

In step 1, you’ll measure the length and width of what you’re painting, and multiply those numbers together to find the square footage. (Hello high school geometry!)

Sounds easy enough. And it is, if what you’re painting happens to be a rectangle or square. But most things in real life aren’t that easy, so you’ll need to use a little reasoning here.

For instance, if you’re painting the walls of a room, you don’t actually want the length and width of the room, but the length and width of each wall. If your room measurement is 12′ x 14′ and your walls are a standard 8′ tall, then there are two walls with 12’x8′ and two with 14’x8′ measurements. Each of the first two walls have 96 square feet to paint, and the other two have 112 square feet to paint. In essence, you’re adding two chunks of 96 sq. ft. and two of 112 sq. ft. for a total of 416 square feet.

The first block on the worksheet is to make notes of these types of measurements and do the calculations until you get to a total number of square feet that you’ll be painting.

(In most cases, a general estimate will be accurate enough, but if you’re struggling to figure out exact square footage of odd shapes, check out my post on calculating square footage for non-math people.)

Paint Worksheet Step 2

In step 2, you’ll convert the number of square feet you’re painting into the number of cans of paint you’ll need to buy.

To make the calculation easier, write the coverage number (from the paint can label) in the first blank. Then you’ll divide the total number of square feet you just calculated in Step 1 by the coverage amount given by the paint manufacturer. That will give you the number of cans of paint that you’ll need for one coat of coverage. You’ll probably want to double that number to allow for two coats.

Pro Tip: Be sure your measurements are in the same units as the manufacturer! Most U.S. manufacturers use square feet as a standard measurement. When you’re measuring your project, use feet, not inches. You can round to the nearest foot or half foot if you need to.

Math Tip: You can’t purchase partial cans of paint, so make sure you round up (not down!) to find out how many cans you’ll need to buy.

Here’s how to get your copy of the paint worksheet.

Tips for Finding How Much Paint You’ll Need

Here are a few tricks for simplifying your calculations:

For Walls:

If your room is close to square, you can simply take the measurements of the longest wall and multiply that total by 4. In the example above, you would use 14’x8’x4 for a total of 448 square feet. This method tends to overestimate the amount of paint you’ll need.

Speaking of overestimating, keep in mind that rooms usually have doors and windows, so the square footage estimate of the wall coverage will usually be a bit on the high side.

For Cabinets:

Make sure you take into account the insides of the cabinet doors. In most cases, this will almost double your square footage if you’re simply measuring the length and width of your whole cabinet.

For Odd-Shaped Projects:

I’m going to go out on a limb here and guess that if you have a truly odd-shaped project, it’s probably a piece of furniture. And in that case, you should by fine with a quart of paint for most table/desk/chair type projects.

More Painting Questions?

It’s entirely possible that this post has raised more questions for you about painting projects, now that you know how much paint to buy. Check out these posts for more information on:

Painting Cabinets

Painting Laminate

Painting Doors

Painting Furniture

Tools to Make Painting Easier

Happy painting, and may you never run out of paint before your project is done!