Limewash goes on thin and soaks into the wall, so the surface decides how far it goes. 40 m² of ordinary render, two coats, at about 6 m² per liter, needs 40 × 2 ÷ 6 = 13.3 liters (3.5 US gallons). Type the area, choose how smooth or rough the surface is – or the coverage printed on your product – and the number of coats, and the calculator gives liters or gallons, the containers to buy and the cost.
Limewash for two coats
| Area | Smooth plaster (10 m²/L) | Ordinary render (6 m²/L) | Rough brick or stone (4 m²/L) |
|---|---|---|---|
| 20 m² (215 ft²) | 4 L | 6.7 L | 10 L |
| 40 m² (431 ft²) | 8 L | 13.3 L | 20 L |
| 60 m² (646 ft²) | 12 L | 20 L | 30 L |
| 100 m² (1,076 ft²) | 20 L | 33.3 L | 50 L |
The same wall can need two and a half times more limewash on old, thirsty brick than on fresh skim coat, so judge the surface as carefully as you measure the area.
Measuring the area
- Walls of a room: the perimeter (all walls added) × the height; take off big windows and doors, ignore small ones.
- A facade: width × height of each wall; for a gable, add width × the height of the triangle ÷ 2.
- Ceilings: length × width.
The area calculator helps with odd shapes.
How limewash behaves
Limewash is applied to a damp wall, in several thin coats, often brushed in different directions. The first coat on porous masonry soaks in and covers less; later coats go further. It suits mineral surfaces – lime plaster, brick, stone, render – that let it bond and breathe; over modern acrylic paint it may not hold, so follow the maker’s advice on primers. Work in shade: hot sun and wind dry it too fast.
The calculator works offline, so you can check quantities at the builder’s merchant with no signal.
Frequently asked questions
How much area does a liter of limewash cover?
Ready-mixed limewash datasheets give about 4–10 m² per liter per coat (roughly 160–400 ft² per US gallon). Smooth plaster is at the top of that range, rough brick and stone at the bottom.
How many coats of limewash do I need?
Usually two; three on bare, porous brick or for a strong color change. One coat can refresh an old limewashed wall.
Why does limewash look different when it dries?
It dries much lighter than it looks wet and stays slightly cloudy and uneven, which is its character. Try a patch and wait a day before judging the color.
How much limewash for a brick house?
Measure the wall area, take off large windows and doors and use the rough setting. 100 m² of brick at 4 m² per liter needs 50 liters for two coats.
Is limewash the same as whitewash or lime paint?
Limewash is lime putty or hydrated lime thinned with water, sometimes tinted; whitewash is an older name, also used for chalk-based mixes. Ready-mixed lime paints vary, so use the coverage on your product's label.
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