How to estimate how much paint you need for a room

You've picked your paint color, you have your brushes and you're anxious to start painting. But how much paint do you need for a room? Running out won't be fun, but overbuying is not the answer, either. Wall texture, your method of application (brush, roller, spray) and how porous the wall is will all affect how much paint you need for each room.

One gallon of paint

A gallon of paint will cover somewhere between 300 and 400 square feet. If you want to estimate on the safer side, go with 300 to 350 square feet per gallon of paint. A room with more than one door and multiple windows will need less paint and may end up in the 375 range. A small amount of extra paint can always be saved for those inevitable touch-ups.

Estimating your paint needs, room by room

An easy way to estimate your paint needs while accounting for architectural features like doors and windows is to use the Walmart paint calculator. With a measuring tape, and some some help from a family member to record the numbers, measure the length and width of each room. If you are painting more than one room the same color, calculate each room separately. You never know, you may change your mind on which color to use in one room once you see the paint chips again in the store.

One coat or two?

The calculator works on the assumption that you need two coats of paint. You can adjust it to one gallon of paint when you:

- won't be painting in a dark color
- Have already primed the walls to create a flat and smooth surface
- aren't trying to paint over a darker hue
- added tint to your primer

One approach is to prime and paint with one coat before buying enough paint for a second coat. The only true way to see how well the coverage and final color looks is to let it dry.

The fifth wall

Unless you have a popcorn ceiling or textured ceiling, always pick out a paint for your ceiling. It's easier to paint the ceiling before the walls, and if you don't paint it first, you'll regret it. To find out how much paint you need for the ceiling, use this formula:

Room width x room width = ceiling area

Tips for even color

Uniform color - Ensure even color by mixing more than one gallon of paint into a larger bucket of paint. Because paint colors can vary slightly from can to can, you'll get the most uniform color by mixing your two or three gallons of paint before you start.

Finish each wall - Always finish with the wall before taking a break or moving onto the next wall.

Written by Pam Gaulin.