How far does a tin of paint go? 1, 2.5, 5 and 10 litres

A tin covers its litres multiplied by the coverage printed on it, divided by the number of coats. At 10 m² per litre, which is BuildBatch’s generic example and not the figure of any paint, a 2.5 L tin covers 25 m² in one coat or 12.5 m² in two, and a 5 L tin covers 50 m² in one coat or 25 m² in two.

The sum

Area one tin covers = litres in the tin × coverage ÷ coats. Coverage is the m² one litre covers in one coat, and it comes from the tin.

What each tin covers at the example figure

At 10 m² per litre, a generic example:

The last column is there because BuildBatch adds 10% to the litres for waste and touch-ups, another labelled example. Its figures are rounded down to one decimal place: 0.1 m² more and the planner buys a second tin.

As wall 2.4 m high, before any door or window is taken off, two coats from a 2.5 L tin is about 5.2 m of wall, from a 5 L tin about 10.4 m and from a 10 L tin about 20.8 m. A 4 m × 3 m room has 14 m of wall round it, so at this coverage one 5 L tin does not give its walls two coats, and one 10 L tin does.

The tin’s own figure decides

The 10 m² per litre is where BuildBatch starts, so that you can get an answer before you have a tin. It is on the cautious side of what most emulsions state. The same sum for two coats, with two other example figures beside it:

None of the three is a maker’s figure. Read the coverage off your tin: if it is given for the whole tin, divide by the litres in the tin, and if it is a range, use the lower figure. Paint coverage explained goes through how tins state it.

What that is in rooms

Four rooms 2.4 m high, each with one internal door 762 mm × 1981 mm and one window 1.2 m × 1.1 m taken off the walls, at the example figures of 2 coats, 10 m² per litre and 10% extra:

Read against the tins:

• One 5 L tin is not enough for the walls of any of these rooms at the example figures. The smallest needs 5.08 L.
• A 5 L tin and a 2.5 L tin, 7.5 L, do the walls of the first three rooms. The 5 m × 4 m room’s 8.882 L is bought as 10 L: two 5 L tins, or one 10 L tin.
• One 2.5 L tin does the ceiling of the two smaller rooms.
• The 12 m² ceiling shows what the 10% does. A 2.5 L tin covers 12.5 m² in two coats, so it would do this ceiling with nothing kept back. With the 10% the sum asks for 2.64 L, which is over one tin.

The 4 m × 3 m room is worked out in full, with the preparation and the tools, in the worked example for painting a 3 × 4 m bedroom.

What changes the answer

• The coverage on the tin. At 14 m² per litre, an example, the 4 m × 3 m room’s walls need 4.835 L rather than 6.77 L, and one 5 L tin does them. At 12 m² per litre, another example, its ceiling needs 2.2 L, and one 2.5 L tin does it.
• The coats. One coat on those walls at 10 m² per litre is 3.385 L. A third coat makes it 10.154 L.
• The surface. Bare or new plaster soaks up paint, and textured, rough or patched surfaces have more surface than their flat area. The tin’s figure is for its stated conditions, usually a sound, sealed, smooth surface.
• The sizes sold. Not every paint comes in every size, or in every colour.

Do it with BuildBatch

Open the room refresh planner with paint chosen, type the room, add the doors and windows and enter the coverage and the tin sizes from your paint. It gives the litres and the tins, with what is left over.

The paint calculator does the same sum for walls and ceilings on one page.

What this guide does not cover

Primer, undercoat or a mist coat on bare plaster, which need their own figures from their own tins. Woodwork. Exterior and masonry paint, which has its own coverage figures. Which tin size costs less, which is in 2.5 litre or 5 litre tin: which costs less?

Related guides

• How much paint do I need?
• Paint coverage explained: m² per litre, per coat
• 2.5 litre or 5 litre tin: which costs less?