How to Estimate Materials for Home Projects
Stop guessing and over-buying — how to estimate paint, tiles, concrete, flooring and bricks for a home project, measure tricky rooms, and add the wastage allowance the pros always include.
Paint Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Paint needed
8
- Exact litres
- 7.27
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Paint Calculator
The Paint Calculator works out your paint needed, along with 1 related figure in an instant. Enter total wall area, number of coats and coverage per litre and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the total wall area.
- Enter the number of coats.
- Enter the coverage per litre.
- Read off your paint needed, together with exact litres — the calculator updates automatically, with no button to press.
Worked example
For example, with total wall area of 400 sq ft, number of coats of 2 and coverage per litre of 110 sq ft/L, the paint needed is 8.
| Total wall area | 400 sq ft |
|---|---|
| Number of coats | 2 |
| Coverage per litre | 110 sq ft/L |
| Paint needed | 8 |
|---|---|
| Exact litres | 7.27 |
Results are estimates for educational use, not professional advice.
Key terms explained
- Area
- The amount of two-dimensional space a shape covers, measured in square units.
Frequently asked questions
Multiply your wall area by the number of coats and divide by the coverage per litre. For 400 sq ft, 2 coats and 110 sq ft/L coverage, you need about 8 litres.
Add the area of each wall (height × width) and subtract large openings like doors and windows. Enter the total square footage to be painted.
Check the paint tin — it is usually 100–140 sq ft per litre. Rough or porous surfaces cover less, so use the lower end if unsure.
Paint is sold in whole tins and you want a little spare for touch-ups, so the calculator rounds up to the next full litre.
Enter the total wall area. Enter the number of coats. Enter the coverage per litre. Read off your paint needed, together with exact litres — the calculator updates automatically, with no button to press.
Related guides
Paint Table: Paint needed by Total wall area
Reference table of paint needed for Paint across a range of total wall area values — exact, engine-computed figures you can read off at a glance.
How to Calculate Paint: Formula, Steps & Examples
Learn how to calculate Paint — the formula explained step by step, with worked examples and a free calculator to check your answer.