Exterior Paint Calculator
Litres and gallons of exterior paint — rough render and fibre-cement drink far more than the can claims.
First coat on unpainted render can drop to 4–5 m²/L — prime or mist-coat first. Buy all colour in one tinting batch and box (intermix) the cans before starting a wall.
Formula
Exterior Paint Calculator is a free exterior paint calculator for civil engineers, contractors and quantity surveyors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Exterior Paint Calculator
Litres and gallons of exterior paint — rough render and fibre-cement drink far more than the can claims. The calculation implements litres = area × coats ÷ coverage (Paint manufacturer spreading-rate data sheets). First coat on unpainted render can drop to 4–5 m²/L — prime or mist-coat first. Buy all colour in one tinting batch and box (intermix) the cans before starting a wall.
How to use Exterior Paint Calculator
- 1Enter Paintable wall area in m².
- 2Enter Coats.
- 3Enter Coverage per litre in m²/L (Smooth 10–11 · light texture 8 · rough render 5–6).
- 4Read Paint needed, US gallons, 10 L cans instantly — no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Exterior Paint Calculator?
- ✓Implements the standard formula — litres = area × coats ÷ coverage
- ✓Reference cited on-page: Paint manufacturer spreading-rate data sheets
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Exterior Paint Calculator use?+
It computes litres = area × coats ÷ coverage, per Paint manufacturer spreading-rate data sheets. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
First coat on unpainted render can drop to 4–5 m²/L — prime or mist-coat first. Buy all colour in one tinting batch and box (intermix) the cans before starting a wall.
Does it include wastage?+
Yes — standard wastage/bulking factors are built in and stated in the formula line, so the quantity is an orderable number, not a bare geometric volume.
Is the Exterior Paint Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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