Buying paint is easy, but you've got to figure out how much paint to buy. You have to know the condition of the walls, ceiling and/or trim you'll be painting, and whether you need a coat of primer first. You also want to include enough paint for touch-ups later on. This is true whether you're hiring a professional painter or plan to do-it-yourself.
This article starts with the preparation every painting project needs in order to be sure you're happy with the results. The best results come from good prep, good paint, and a good brush and/or roller.
We've created a worksheet to help you calculate how much paint to buy before you begin your project. It can be very frustrating to run out of paint and have to go back to the store. You also don't want to buy too much paint, since disposing of paint may not be easy depending on your town's regulations.
The quality of any painting project is based on attention to detail. The paint surface must be prepared properly. You need to fill in nicks and cracks with spackle, and caulk where the walls touch doors, windows and trim.
You also want to use a quality paint and apply it with a quality paintbrush, both of which you should purchase at a paint store where the staff can answer other questions you might have.
- Walls are usually flat (low traffic) or satin (high traffic) finish.
- Ceilings are usually flat and by using the same color throughout your house, you can save on paint.
- Trim is most often semi-gloss, or high gloss if you want a very hard/shiny surface.
Next comes the preparation, which can greatly change the way the paint looks when done. In fact, most people assume that all you do is get some paint and one coat does it all. This couldn't be further from the truth. You've got to repair imperfections first, then go over rest of the surface to get good adhesion of your final paint coat.
- Patch holes, sand rough spots, and use a primer on new sheet rock. Use a stain block like Kilz as needed.
- Apply 2 coats when painting unfinished or heavily patched walls, or when covering dark colors.
- Do not use cheap paint (minimum $20/gallon) or you'll need to apply an extra coat of paint, which ends up costing more.
- Buy some extra paint for small repairs by rounding up to the nearest gallon. (The cost of a gallon is usually about the same as 2+ quarts, so you might as well just purchase the gallon.)
It's always hard to know which tools get the best results, so here are ones recommended by friends who are professional painters meaning they do this every day.
Calculating How Much Paint to Buy
Here's a worksheet to help determine how much paint to buy. The example is for a 10 x 14 ft room with 2 doors, 2 windows and ceiling height of 8 ft (average). Most paint covers 350 sq ft per gallon, but it's best to review the label, especially when using a paint that says it only needs one coat.
|Sample WALL Calculation||Sample Room||Room #1||Room #2||Room #3|
|Add length of all walls = linear ft (LF)||48 lf|
|Multiply LF x ceiling height = sq ft||384 sq ft|
|Subtract doors (20 sq ft/door)||344 sq ft|
|Subtract windows (15 sq ft/window)||314 sq ft|
|For 2 coats, multiply by 2||628 sq ft|
|Add 10% contingency||691 sq ft|
|Divide by 350 sq ft/gallon||2.0 gal|
|Sample CEILING Calculation||Sample Room||Room #1||Room #2||Room #3|
|Use 2 longest walls for ceiling sq ft||168 sq ft|
|For 2 coats, multiply by 2||336 sq ft|
|Add 10% contingency||370 gal|
|Divide by 350 sq ft/gallon||1.1 gal|
|Sample TRIM Calculation||Sample Room||Room #1||Room #2||Room #3|
|Calculate the LF for all 4 walls, including closets with baseboard||48 lf|
|Add door trim (20 lf/door for sides + door width for top trim)||88 lf|
|Add window trim (use 15 lf/window)||118 lf|
|Calculate LF x 0.5 (6 in) to get sq ft||59 sq ft|
|Add 10% contingency||0.2 gal|
And we've got lots more painting articles. Here are ones you might find helpful right now:
- Types of Paint Finishes: Matte, Eggshell, Satin …
- Paint Colors and Lighting
- Painting Mistakes You Don't Want to Make
- How to Safely Dispose of Paint