Painting / Materials
Plan a paint order
Use your measured area and the coverage on the paint label to see how many tins to buy.
Describe the job instead
Product order
How many tins?
Enter surface area square metres.
How it works
Put in your numbers
Use your own rates, times and measurements.
See your answer straight away
It works it out as you type.
Copy or print it
Send it on, or keep it with the job.
What it covers: Turn room size, coats and label coverage into whole tins of paint and primer.
Free to use. No sign-in needed.
How to work out how much paint you need
Paint quantity comes down to three things: the area you are painting, the number of coats, and the coverage printed on the paint you plan to buy. Divide the total area to cover by the coverage to find how much paint you need, then round up to whole tins. Do the same for primer if the surface needs it.
- Enter the paintable area in square metres or square feet. To work it out from a room, open Work out the area from a room and enter the length, width and height, the number of doors and windows and their sizes. Tick Include the ceiling if it takes the same paint.
- Enter the number of coats you plan to apply.
- Enter the coverage on the product label, in square metres per litre or square feet per gallon, and the tin size in litres or gallons.
- Add an extra allowance as a percentage for touch-ups or a difficult surface. It is added to the paint needed before rounding up to whole tins.
- If the surface needs primer or undercoat, enter the primer coats, its coverage and its tin size. Primer uses the same area and allowance.
- Read the tins to order, the paint needed and what the whole tins supply. Add a price per tin of paint and of primer if you want a materials cost.
Tips and common mistakes
- Always use the coverage on the label of the paint you are buying. Coverage changes between products and finishes.
- Rough, porous or freshly plastered surfaces soak up more paint, so actual coverage can be lower than the label suggests.
- Strong colour changes may need more coats or a primer. Plan for this before ordering.
- Buy all the tins for one area at the same time where you can, so the colour matches across the job.
Questions
How much paint do I need for a room?
Work out the wall area by multiplying the room's perimeter by its height, and take off windows and doors. Multiply by the number of coats, then divide by the coverage on the paint label. Round up to whole tins.
How many litres of paint do I need per square metre?
It depends on the product. Check the label for its coverage, usually given as square metres per litre, and divide your area by that figure for each coat. Rough or porous surfaces may need more.
How many coats of paint do I need?
It depends on the surface, the paint and the colour change. A repaint in a similar colour often needs fewer coats than a big colour change or a new surface. Check the product advice and plan your order for the number of coats you expect.
Do I need primer before painting?
New, bare, stained or very porous surfaces often need a primer so the topcoat covers evenly. Work out primer the same way as paint, using the primer's own coverage. Check the paint label for its advice.
How do I work out paint for a ceiling?
Multiply the room length by the width to get the ceiling area. Multiply by the number of coats and divide by the coverage of your ceiling paint. Round up to whole tins. In the calculator, Include the ceiling adds it to the walls, so work the ceiling out separately if it uses a different paint.
Add this calculator to your website
Free for any website, blog or trade association page. Paste this code where you want the calculator to appear.