Paint calculator.
How much paint does a room need? Enter its size and the number of coats, and we work out gallons and litres.
It's free, and it runs in your browser. Nothing you type is sent anywhere or saved.
Enter the room.
Measuring rooms from a floor-plan PDF? QWIKIT Plans is being built to do it for you.
Join the waitlistHow it's worked out.
Wall area is the room's perimeter times the ceiling height, less 20 sq ft for each door and 15 sq ft for each window. The ceiling, if you include it, is the length times the width.
We multiply by the number of coats and divide by the coverage. 350 sq ft per gallon (3.78 L) is a typical figure, but the label on your paint is the one to use. The amount to buy is rounded up to the nearest quart.
What it can't tell you.
- Trim, doors, textured walls, new drywall, and a dark colour covered by a light one can all need more paint or more coats.
- Use one calculation for each room that has a different ceiling height or finish.
- The result is an estimate. Rounding up and keeping a little extra for touch-ups is usually wise.
These are estimates from common rules of thumb. Check them against your supplier's advice and your own plans before you order.
Questions.
How much paint do I need for a 12 by 10 foot room?
With 8 ft ceilings, one door and one window, the walls come to 317 sq ft. Two coats cover 634 sq ft, which is about 1.8 gallons at 350 sq ft per gallon, so buy 2 gallons. Painting the ceiling too brings it to about 2.5 gallons.
How much does a gallon of paint cover?
The calculator starts at 350 sq ft per US gallon for one coat. The label on your paint is the one to use, and you can type its figure into the coverage box.
How many coats should I plan for?
The calculator starts at two coats. A dark colour covered by a light one, new drywall or a textured wall can need more, so change the number to match your job.
Does the paint calculator show litres?
Yes. It shows US gallons and litres (1 US gallon is 3.785 litres), and it rounds the amount to buy up to the nearest quart, which is a quarter of a gallon.
Is what I type saved or sent anywhere?
No. The calculator runs in your browser. Nothing you type is sent anywhere or saved.
More free calculators.
What if you didn't have to do this by hand anymore?
You just typed a room's measurements in yourself. QWIKIT Plans is desktop software for Windows and Mac that we're building to read rooms, walls and openings from a floor-plan PDF instead. The app is not released yet, and joining the waitlist is free.
Join the QWIKIT Plans waitlist