Home
Litres of paint required
Dividing the total painted area by the per-litre coverage gives the volume of paint, before any rounding to tins.
The Formula
Litres = (wall area x coats) / coverage per litre
Dividing the total painted area by the per-litre coverage gives the volume of paint, before any rounding to tins.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| R | Coverage per litre per coat | square metres per litre | Quoted on the tin, typically 12 m2 per litre for emulsion on smooth walls. |
| A x c | Total painted area | square metres | The wall area already multiplied by the number of coats. |
| L | Litres of paint needed | litres | A continuous volume, which the shop then rounds up to whole tins. |
What Each Symbol Means
Rsquare metres per litre
Coverage per litre per coat
Quoted on the tin, typically 12 m2 per litre for emulsion on smooth walls.
A x csquare metres
Total painted area
The wall area already multiplied by the number of coats.
Llitres
Litres of paint needed
A continuous volume, which the shop then rounds up to whole tins.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate paint coverage page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Paint Coverage, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.