CalcVind

Paint Calculator

How many litres of paint for your room

Room Size

Room
Leave out

On the tin. Interior emulsions: about 100–140

sq ft per litre

Paint Needed

6.5 litresPaint
4 litresPrimer (1 coat)
389 sq ftArea to paint
440 sq ft
Walls
−51 sq ft
Doors and windows
1 × 10 L
Suggested buy
Read the guide · 4 minHow Much Paint Do I Need for a Room?Read the guide · 6 minHow Many Bricks, Cement and Steel for a 1,000 sq ft House?
  1. 1
    Enter the room size
    Length, width and height
  2. 2
    Leave out doors and windows
    And choose walls or ceiling too
  3. 3
    See the litres
    Paint and primer

How is paint quantity calculated?

Work out the wall area, take out doors (about 21 sq ft) and windows (about 15 sq ft), then divide by the paint's coverage for each coat.

Wall area = 2 × (length + width) × height − doors − windows

Paint (litres) = area × coats ÷ coverage per litre

Coverage varies

Coverage depends on the paint and the surface: smooth, primed walls take less paint than new plaster or rough walls. Check the tin: premium interior emulsions often cover 120–140 sq ft per litre per coat, distempers less.

Primer and putty

New plaster needs a coat of primer, and wall putty for a smooth finish. Repainting a sound, already-painted wall in a similar colour often needs no primer.

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Frequently asked questions

How much paint for a 10 × 12 room?

With 10 ft walls, one door and two windows, about 389 sq ft of wall: roughly 6.5 litres for two coats at 120 sq ft per litre.

How many coats should I apply?

Two coats for a fresh colour or new walls; one may do when repainting the same colour on a sound surface.

How much area does 1 litre of paint cover?

About 100–140 sq ft per coat for most interior emulsions on smooth, primed walls.

Last reviewed: October 2026