Paint Calculator
Calculate how many litres of paint you need from the wall area, number of coats and coverage.
Formula last reviewed 4 August 2026 · How we verify our calculators
Paint required
16.7 L
Updates live as you type
Frequently asked questions
Multiply the area by the number of coats and divide by the paint’s coverage per litre. 1,000 sq ft at two coats with 120 sq ft/L coverage needs about 16.7 litres.
Coverage varies by paint type and surface — typically 100–140 sq ft per litre. Use the figure on your paint can; rough or porous surfaces consume more.
Two coats is standard for good, even colour. A drastic colour change or a fresh, porous surface may need a primer plus two coats.
For a quick estimate you can use the gross wall area; subtracting large openings gives a tighter figure. Always keep a little extra for touch-ups.
One extra coat, 8.3 more litres — know that before you buy
1,000 sq ft, 2 coats, at a coverage rate of 120 sq ft per litre, needs (1,000 × 2) ÷ 120 = 16.67, rounded up to 16.7 litres. Add a third coat — common for a bold colour change over a darker existing shade — and the requirement jumps to (1,000 × 3) ÷ 120 = 25 litres, a proportional increase since litres scale directly with coat count. Knowing that gap before buying is the difference between one trip to the store and two.
Why coverage rate is the number worth double-checking, not guessing
Coverage varies meaningfully by surface and product — smooth, well-primed walls sit near the top of the typical 100–140 sq ft/L range, while rough, porous or freshly plastered surfaces drink noticeably more paint for the same area. The figure printed on the paint can itself is the right one to enter here, not a generic assumption, since this single input scales the entire estimate.
What effectively counts as an extra "coat"
A bold colour change — light going dark, or the reverse — often needs a primer coat first to get even coverage, and that primer coat functions exactly like an additional coat in this calculation: it adds proportionally to the total litres required, the same as any other pass of paint over the surface.
This is an estimate for planning purposes. Always add a wastage margin and confirm exact quantities with your contractor or engineer before ordering materials. Keep a small surplus tin for touch-ups and future repairs — exactly matching a colour and finish months or years later is often difficult once a specific batch is discontinued. Pair this with the tile calculator when planning a full room finish, so walls and floor get budgeted from the same set of room dimensions rather than measured twice.