Calculating How Much Paint You Need

Whether you are on your first DIY project or you’re a seasoned veteran, you have to ask yourself each time, “How much paint do I need?” There are several paint calculators on the internet to help guide you, but ultimately there are certain measurements you have to make yourself. There are also questions you must address about the quality of different paints and the types of walls you are covering.

Measuring the Space

For a plain wall, the measurement is easily calculated by multiplying the width of the wall by the height. A wall that is 12 x 10 is 120 square feet and you are painting the entire space. For walls with windows, doors or other areas you aren’t painting, the space they take up must be subtracted from the calculation. For example, if a 120 foot square foot wall has a 3 x 4 foot window, that window takes up 12 feet of square space. You need enough paint in that case to cover 108 square feet of wall space. Make sure you also eliminate any other space taken up by moldings and other areas you aren’t painting. Once you have measured all of the walls in the room you are painting, and subtracted unpainted space, add those numbers to get the total square feet of the room to determine your paint needs.

Account For Existing Wall Coverings

If you are painting a dark wall with a lighter paint, you may need two coats in order to get the desired effect. You might consider using a primer before you start painting if you don’t want to use two coats. You should also account for the type of wall you are painting. In general, a gallon of paint covers between 300 and 400 square feet, though you should check the paint you’ve selected to see the exact manufacturer’s specifications. Porous surfaces require more paint, as do textured surfaces to be sure you don’t leave any unpainted spaces, or areas where the hues don’t match on the same wall. If you are painting a smooth space you can stretch that gallon of paint much further.

Paint Quality

It may be tempting to go with a cheaper paint, but many cheaper paints are thinner than their higher-quality counterparts. If you need two coats of a cheaper paint to cover your walls, you aren’t saving money by buying the cheaper alternative. In the end, what you are doing is taking twice as much time finishing a job that could have been finished with one coat. Better quality paints also last longer, meaning you won’t be looking at the same room again in five years and wondering, “How much paint do I need?”