How To Calculate Paint Quantity For Any Project

Quick and Easy Tip: How to calculate paint for any project!

When it comes to painting projects, how do you figure out how much paint you’ll need? Most of us probably ask the clerk at the paint desk how much we should get. And normally this is fine, but what if the clerk is new to the paint department? Even worse, what if they don’t care and happen to mutter the first random thought that comes to mind?  My experience at most home improvement stores is that it’s really the luck of draw as to whether you get someone who truly cares about helping you with your project, or whether they’re just watching the clock until it’s time to go home! That said, why not stop relying on someone else and find out how to do the math yourself!

Get your tape measure ready! First thing you’ll need to do is measure the area you are painting.  Because you aren’t measuring for blinds or tile, you don’t have to be exact. Say your walls measure 8 feet and 5 inches, I’d just round-up to nine and call it good. This way you are less likely to short yourself.  Getting back to the act of measuring, if all the walls are the same height than you only need to measure one. Because odds are pretty good that you’ll just come up with the same number. If you’ve got a half wall or something not square you’ll want to measure all the “odd” walls as well.  Now that you’ve got the height down, it’s time to measure the width of all your walls. Once again I’d continue to round-up to the nearest foot when marking your measurements.

Do the Math! Once you’ve got the measurements of the areas you want to paint it is time to do the math.  If you are painting one area a different color than another then you will want to separate the measurements by color.  First you start out by converting each wall into square feet. For example: let’s say you’ve got a wall that is 10 feet wide by 8 feet tall. This would equal out as 8ft x 10ft = 80ft.  The next wall is 15ft wide and is the same height. Therefore, this comes out to 15ft x 8ft  for a total of 120sf.  Wait, there’s one last step! If you add the two separate areas together, you get a grand total of 200 square feet that you’re looking to paint.

How To Calculate Paint Quantity For Any ProjectMultiple coats? Okay, so you’ve got the measurements, now what?  Well, you’ll need to determine if you need to paint more than one coat of paint on each surface.  I would say as a general rule, expect to paint two coats of anything that isn’t considered a really light color when painting over a white wall surface. So even though you have only 200 square feet of wall, you’ll need to double that footage calculation because you’re painting two coats. The two coats of paint breaks down as follows: 200 square feet x 2 = 400 square feet.

Width X Height = Square Feet X 2 (for multiple coats) = the amount of wall space you will need to cover.

Now that you know how much paint you need for your project, how do you know how much paint to actually buy?  Well, the easiest way is to look at the back of the paint can itself and see what the recommended coverage is according to the paint company. If this doesn’t make you comfortable, then instead you could use the general painter’s rule that one gallon of paint will cover up to 400 square feet. One quart of paint on the other hand, will cover up to 100 square feet. Please understand  that “I say up to” because it depends on the paint as to how well it covers. Therefore, this is where reading the back of the paint can comes in handy. Just remember though, the manufacturer’s recommendations and your actual painting project results may vary.

Speaking for myself, I usually try to error on the side of caution and purchase more paint than I think I’ll need.  This works well for me because I often have additional projects I want to tackle and the extra paint comes in handy. Also, if you do the math and find that you need exactly one gallon and two quarts, I would consider just purchasing two gallons. Often times it costs just as much for two quarts as it does for an entire gallon!