About this calculator
Stain, oil or sealer for a whole deck, including both faces of the railings and the steps, adjusted for weathered wood.
How it’s calculated
Area = deck + 2 × railing length × height × 1.2 (allowance for spindles) + steps. Amount = area × coats ÷ coverage. Rough or weathered wood is assumed to drink about a third more.
Worked example
With these inputs:
- Deck length
- 16 ft
- Deck width
- 12 ft
- Railing length
- 28 ft
- Railing height
- 36 in
- Steps
- 3
- Wood condition
- New / smooth
- Coats
- 2
- Coverage (sq ft per gallon)
- 250
the result is:
- Stain needed
- 3.27 gal
- Deck surface
- 192 sq ft
- Railing (both faces)
- 201.6 sq ft
- Total area
- 408.4 sq ft
Tips from the trade
- Clean and brighten the wood first. Stain won’t stick to grey fibres.
- Do a water-drop test: if water beads, the wood isn’t ready to take stain.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and local building codes before ordering.