Inputs
US unitsDeck sections
| # | Length | Width | Area | |
|---|---|---|---|---|
| 1 | 240.00 sq ft |
Extras
Results
Example data table
Illustrative scenarios using 350 sq ft/gal, waste and method as noted.
| Scenario | Deck | Extras | Coats | Waste | Method | Gallons | Liters |
|---|---|---|---|---|---|---|---|
| A | 16×12 | None | 2 | 10% | Brush | 1.21 | 4.57 |
| B | 20×14 | Rails 50×3, both sides | 2 | 15% | Sprayer | 4.38 | 16.59 |
| C | 12×12 | Stairs 4×1×3, posts 6×0.25×3 | 1 | 10%+porosity 10% | Brush | 0.60 | 2.28 |
Formula used
For each section: Area = length × width.
Rails area = perimeter × height × sides.
Stairs area = steps × tread depth × width.
Posts area ≈ count × (4 × post width) × post height.
Balusters area ≈ count × baluster width × baluster height.
Base area = deck sections + rails + stairs + posts + balusters.
Adjusted area = Base × Coats × (1 + Waste%) × (1 + Porosity%) × Method factor.
Required volume = Adjusted area ÷ Coverage rate.
Coverage rate units: sq ft/gal (US) or m²/L (Metric).
How to use this calculator
- Select the unit system and enter the coverage printed on your stain.
- Add deck sections. Include rails, stairs, posts, and balusters if applicable.
- Set coats, waste/overlap, porosity (old wood), and application method.
- Review totals, required volume, and rounded purchase guidance.
- Export your inputs and results using CSV or PDF buttons.
Tip: For older, rough-sawn, or weathered wood, increase porosity and waste.
Typical coverage rates by stain type
Use the label on your specific product; values below are planning ranges.
| Type | Range (sq ft/gal) | Range (m²/L) |
|---|---|---|
| Transparent / Toner | 300–400 | 7.4–9.8 |
| Semi‑transparent | 250–350 | 6.1–8.6 |
| Solid / Opaque | 150–300 | 3.7–7.4 |
| Deck paint / Elastomeric | 100–200 | 2.5–4.9 |
Surface condition and texture multipliers
These multipliers increase the adjusted area before dividing by coverage.
- Planed, smooth boards: ×1.00
- Lightly weathered / open grain: ×1.05–1.15
- Rough‑sawn lumber: ×1.20–1.35
- Grooved/composite profiles: ×1.10–1.25
- End‑grain heavy exposure: add +5–10% waste
Railing and baluster quick area guide
Approximate exposed area per linear length of railing (height × sides).
| Railing height | Sides | Area per linear foot | Area per meter |
|---|---|---|---|
| 36 in (0.91 m) | One side | ≈ 3.0 sq ft / lf | ≈ 0.28 m² / m |
| 36 in (0.91 m) | Both sides | ≈ 6.0 sq ft / lf | ≈ 0.56 m² / m |
| 42 in (1.07 m) | One side | ≈ 3.5 sq ft / lf | ≈ 0.33 m² / m |
| 42 in (1.07 m) | Both sides | ≈ 7.0 sq ft / lf | ≈ 0.65 m² / m |
Include posts and balusters separately for precision; this guide is for panels.