Buying too little paint means a second trip, and too much is money wasted. Enter the size of the room, the area of the doors and windows and the coverage from your tin, and this calculator gives the litres you need, with a little spare.
How to Use It
Measure the room in metres. The coverage is printed on the tin, as square metres per litre, and varies between paints. Most walls need two coats. Tick the box to include the ceiling in the same paint.
A Worked Example
A room 4 metres by 3.5 metres with 2.4 metre walls has 36 square metres of wall. Take away 4 square metres for a door and a window and you have 32. Two coats is 64 square metres, which at 12 square metres a litre is 5.33 litres. With 10% spare, buy about 5.9 litres.
What Can Change the Amount
Rough or freshly plastered walls soak up more paint, and a big colour change usually needs an extra coat. Ceilings and woodwork take different paint, so work them out separately.
Questions about Paint Calculator
How many coats of paint do I need?
Most walls need two coats. New plaster, bare wood and a change from a dark colour to a light one can need three, and a primer or mist coat first.
Where do I find how far a tin of paint goes?
The coverage is printed on the tin, usually as square metres per litre. It assumes a smooth, sealed wall, so rough walls will not go as far.
Should I leave out the doors and windows?
Yes, take the area of doors and windows off, as you will not be painting them. A door is about 1.6 square metres and a typical window about 1.5.