Paint planning, made clearer
Guides
Get a clearer paint estimate before you start. These guides explain how to measure a room, read the coverage on a paint can, choose coats, sheen and primer, and work out the cost. Each one has a worked example and the sources behind it.
Browse the guides
9 guides
How to measure walls for paint
Measure a room's walls in feet, subtract doors and windows, and turn the square footage into gallons and quarts of paint.
5 min readUpdated October 10, 2026
How paint coverage works
What the square feet per gallon figure on a paint can means, why new drywall and texture lower it, and how to turn it into gallons.
5 min readUpdated October 10, 2026
How many coats of paint you need
When one coat of paint is enough, when to plan for two or three, and how primer on new drywall or a big color change affects gallons.
5 min readUpdated October 10, 2026
How much paint for a ceiling
Measure a flat or sloped ceiling, pick a ceiling paint and estimate gallons for smooth and popcorn ceilings, with a worked 12 × 10 ft example.
6 min readUpdated October 10, 2026
When you need primer (and how much)
When new drywall, patches, stains, glossy trim, bare wood or a big color change call for primer, and how to work out how many gallons to buy.
5 min readUpdated October 10, 2026
How much it costs to paint a room yourself
A DIY cost breakdown for painting a room: gallons of paint, primer when you need it, and the rollers, tape, brushes and drop cloths.
5 min readUpdated October 10, 2026
Paint sheens explained: flat to high-gloss
Flat, eggshell, satin, semi-gloss and gloss compared: where each sheen belongs, how well it cleans, and how it hides or shows flaws.
5 min readUpdated October 10, 2026
Paint can sizes and what each covers
What a quart, a gallon and a 5-gallon bucket of paint cover, when to buy each size, and how many cans a typical room needs.
5 min readUpdated October 10, 2026
How much paint to paint a house exterior
Measure walls and gables, subtract doors and windows, allow for siding texture and primer, and turn a house exterior into gallons of paint.
7 min readUpdated October 10, 2026
Start with your painting question
Pick the part of the job you are planning. Each guide explains what to check, what changes the estimate, and where to go next.
How much paint will cover my walls?
Read the coverage on a paint can and see why new drywall and textured walls take more.
Understand paint coverageHow many coats should I plan?
When one coat is enough, when to plan for three, and where primer fits in.
Choose the number of coatsDo I need primer?
New drywall, stains, glossy trim and big color changes: when primer is worth it and how much to buy.
Decide on primerWhat will it cost?
Paint, primer and supplies for a typical room, with a worked example.
Budget the jobQuart, gallon or 5-gallon bucket?
What each can size covers and how to buy the fewest cans.
Compare can sizesA quick way to estimate wall paint
Measure the room length, width and wall height. Find the coverage rate on the paint can, then account for the coats and the wall surface. This gives a planning estimate; product directions and surface preparation still matter.
| Check | How it affects your estimate | Where to find help |
|---|---|---|
| Wall area | 2 × (room length + room width) × wall height | Use the calculator for the room calculation |
| Doors and windows | Subtract their area from the wall area; reveals may use some paint | Enter the openings in the calculator |
| Coverage on the can | A higher sq ft per gallon rate means less paint per coat | Coverage guide |
| Coats and surface | Multiply by every coat; porous or rough walls can need more | Coats and coverage guides |
Before you buy
- Check the product label for coverage, preparation, drying time and recoat instructions.
- Prepare the wall and use a suitable primer where the surface and paint system call for it.
- Compare your estimate with available can sizes and keep a little paint sealed for touch-ups.
Ready to estimate?
Use the paint calculator to turn your measurements into gallons and cans.