Calculate how many litres of decking or fence stain you need based on the area and number of coats.
Enter the length and width of the deck or fence area to be treated, set the number of coats (two is typical on new timber), and adjust the coverage rate if your product differs. The tool returns how much wood stain, decking oil or preservative to buy. It works in litres or US gallons.
| Product | Coverage |
|---|---|
| Wood stain | ≈ 10 m²/L (400 ft²/gal) |
| Decking oil | ≈ 12 m²/L |
| Rough-sawn timber | Absorbs 2–3× more |
A 5 m × 4 m deck = 20 m². At 10 m²/L for two coats you need 20 ÷ 10 × 2 = 4 litres. Rough or previously bare timber can soak up far more on the first coat, so buy a little extra.
Tip: apply thin coats and work with the grain; two thin coats last far longer than one heavy coat that sits on the surface.
As a rule of thumb, one litre covers about 10 square metres per coat on smooth timber. Rough or thirsty timber can halve that on the first coat.
Two coats is standard for new or bare timber. A single maintenance coat is often enough on previously stained surfaces.
For the longest life, yes. If you are coating both faces, double the area or run the calculation twice.
Most decking stains are touch-dry in 1–2 hours and ready for a second coat after 4–6 hours, depending on the product. Allow 24–48 hours before heavy use, and avoid staining if rain is forecast.
Stain in dry, mild weather — ideally 10–25°C (50–77°F) with no rain forecast for 24–48 hours. Spring or early autumn is ideal; avoid direct hot sun, which dries the stain too quickly.
