Fence Paint / Stain Calculator
Calculate how many gallons or liters of paint or stain you need for your fence.
Enter fence dimensions and number of sides to coat.
Fence paint coverage calculation ensures you buy the right amount of paint or stain for your project without multiple trips to the store. Fence boards have a surprisingly large surface area when both sides and edges are counted.
The Formula:
Total area (m²) = (Total linear meters of fence × Height × 2 sides) + (Post area × Number of posts)
Paint needed (liters) = Total area / Coverage rate per liter
Coverage Rates by Product:
| Product Type | Coverage per Liter |
|---|---|
| Exterior wood paint (first coat) | 8–10 m² |
| Exterior wood paint (second coat) | 10–12 m² |
| Wood stain / preservative | 5–8 m² (very porous wood) |
| Fence sprayer application | 6–8 m² per liter |
| Decking oil | 4–6 m² |
Waste Factor: Add 10–15% for laps, spills, and board texture variation.
Worked Example:
Fence: 20 m long, 1.8 m high, painted both sides, 20 wooden posts (each 0.1 m × 1.8 m × 4 sides):
- Board area (both sides): 20 × 1.8 × 2 = 72 m²
- Post area: 20 × (0.1 × 1.8 × 4) = 20 × 0.72 = 14.4 m²
- Total: 86.4 m²
- With 10% waste: 95 m²
Two coats needed. Total paint = 95 × 2 = 190 m² ÷ 10 m²/liter = 19 liters
Buy: 20 liters (standard tin size)
Practical Tips:
- Apply preservative first on new or bare wood — paint alone doesn’t protect against rot
- Never paint wet or damp wood — moisture trapped underneath causes peeling within months
- A garden sprayer cuts application time by 60% vs brush, but requires masking nearby plants
- Semi-transparent stains last 3–5 years; opaque paint lasts 5–7 years but hides natural grain
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.