how much paint do i need?
Interior painting generally doesn’t require much expertise. Many people do it on their own, but, before you start, it’s important to know how much paint to buy. The project’s exact scope depends on the size of the room and the surfaces you intend to paint. Generally, a painting project requires two coats or more. That’s something to consider when doing the math.
Tips on Determining Paint Coverage
Mathematical calculations are needed to accurately determine the amount of paint to use. This must be done for each surface you plan to coat. We’ll provide some examples and how to measure a room below. First, here are some general tips and rules of thumb:
- About one gallon of paint will cover 350 square feet of wall in a single coat.
- For unfinished, dark, or heavily patched walls, at least two coats of paint are needed.
- Unpainted drywall absorbs some paint, so you’ll need to buy a special primer.
The color you use also affects the amount of paint needed, as does making a dramatic color change from the underlying coat. Primer is an important factor, here. Adding a darker tint to a white primer can help; the closer this tint is to the paint colors, the better the result will be.
Determining the square footage of a wall requires just a simple formula. Just multiply the width by the height, so a 10-foot-high wall that is 12 feet long is 120 square feet.
For doors and windows, the same concept applies. If a door opening measures 20 square feet, then that number would have to be subtracted from the total wall area. That leaves you with 100 square feet of wall to paint.
Given the value of 350 square feet per gallon, divide the wall coverage by that number (100/350), and the answer is 0.28 gallons. A larger wall of 250 square feet would require 0.71 gallons. You could, therefore, round up to a gallon, assuming a single coat will be applied.
Measuring the Entire Room
Painting an entire room requires completing the same measurements for each wall, minus the total surface area of each door and window. To determine the total, add up every wall (with every subtracted area eliminated from the equation) so you know the total wall area.
Assuming a room of 1,000 square feet, the standard calculation would yield just over three gallons of paint. However, most people don’t need an extra gallon sitting around. Supply stores sell paint in non-average size containers. Buy an extra quart, and you have some left for touch-ups.
To make things easier, you could use an online paint calculator, which will do the math for you.
Considering Solid Walls, Ceilings, Trim, and Other Extras
For solid walls and ceilings, the same total length times width calculation yields their area. Trim is a different story. Measure the length in feet, times ½ foot to account for a typical width. This goes for trims around windows, doors, ceilings, built-in furniture, and baseboards. Subtract the trim totals if you don’t want to paint them; add them in if a coat of paint will be applied.
If you need help in deciding how much paint to buy, contact Brinkmann’s today.