Paint Quantity Calculator
Coverage per litre varies by product; interior water-based paints typically cover 8–12 m² per litre.
Your numbers
Paint needed
8L
Area
80m²
Formula
Paint needed = Area × Coats ÷ Result
Dark colours over white walls often need three coats for an even finish — buy about 10% extra.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Area (m²)The space a shape covers — length squared. | 40 | 0 and up |
| CoatsHow many coats you paint; two coats means twice the paint. | 2 | 1 ~ 5 |
| Result (m²)What the formula gives back — the answer this page is for. | 10 | 1 and up |
Step by step
Quick reference table
Results when only Area (m²) changes and everything else stays put.
| Area (m²) | Paint needed (L) | Area (m²) |
|---|---|---|
| 20 | 4 | 40 |
| 30 | 6 | 60 |
| 40 | 8 | 80 |
| 60 | 12 | 120 |
| 80 | 16 | 160 |
What each result means
| Result | At default values |
|---|---|
| Paint needed (L)How much paint you need — buy up to whole tins. | 8 |
| Area (m²)The space a shape covers — length squared. | 80 |
Common mistakes
Dark colours over white walls often need three coats for an even finish — buy about 10% extra.
Glossary
- Area
- The space a shape covers — length squared.
- Coats
- How many coats you paint; two coats means twice the paint.
- Result
- What the formula gives back — the answer this page is for.
- Paint needed
- How much paint you need — buy up to whole tins.
Frequently asked questions
Q. How is Paint Quantity Calculator calculated?
Paint needed = Area × Coats ÷ Result — Coverage per litre varies by product; interior water-based paints typically cover 8–12 m² per litre.
Q. Can you walk through an example?
With Area 40m², Coats 2, Result 10m², the answer is Paint needed 8L.
Q. What do I need to enter?
Enter Area, Coats, Result. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Area (m²) moves the answer to Area (m²) 20 → Paint needed (L) 4 and Area (m²) 80 → Paint needed (L) 16. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Dark colours over white walls often need three coats for an even finish — buy about 10% extra.
Related calculators
Keep your length units consistent across inputs — mixing centimetres and metres throws results far off.