Inputs
Open gaps reduce surface by this percent.
Accounts for gaps between pickets/boards.
ft² per gallon
Base rating at 1 coat on smooth softwood.
$
per gallon
Used for cost estimates and container mixes.
Results
Total area
0 ft²
Effective coverage
0 ft²/gal
Required volume
0.00 gal
Est. material cost
$0
| Container plan | Total volume | Est. cost | Overage |
|---|---|---|---|
| Run a calculation to see a plan. | |||
Container prices assume typical bulk discounts; override price as needed.
Estimated time
—
Example data
| Scenario | Dimensions | Coats | Method | Coverage rating | Waste | Est. volume |
|---|---|---|---|---|---|---|
| Deck with railings | 16×12 ft deck, rail 24×3 ft | 2 | Brush | 300 ft²/gal | 10% | ~2.4 gal |
| Privacy fence | 80×6 ft, 90% solid, both sides | 1 | Spray | 300 ft²/gal | 10% | ~3.5 gal |
| Clapboard siding | Wall 600 ft² minus 80 ft² openings | 2 | Roller | 300 ft²/gal | 10% | ~3.0 gal |
Numbers above are illustrative; use your exact inputs for accurate plans.
Formula used
- Base area depends on project:
- Deck:
deck_area = length × width × (1 − gaps%); - Railings:
rail_area = railing_length × railing_height × rail_sides; - Fence:
fence_area = length × height × solid% × sides; - Siding:
siding_area = wall_area − openings; - Custom:
custom_area × (1 + extras%).
- Deck:
- Total stainable area: sum of relevant areas.
- Effective coverage per container:
eff_coverage = base_coverage × method_factor × transparency_factor ÷ (wood_factor × roughness_factor) - Required volume:
volume = area × coats × (1 + waste%) ÷ eff_coverage - Container planning: choose a mix of sizes that meets or slightly exceeds required volume with minimal overage and reasonable container count.
Production time uses typical rates by method and scales with coats.
How to use
- Select units and project type. Enter dimensions or area.
- Set coats, waste allowance, method, wood type, and surface condition.
- Confirm your product’s coverage rating and container price.
- Click Calculate to see area, volume, cost, and container plan.
- Use Export CSV or Export PDF to save or share.
Always follow product label directions; this tool provides planning estimates.
Calculation snapshot
Reference data
Exterior wood stain coverage chart
| Transparency | Smooth softwood (ft²/gal) | Rough softwood (ft²/gal) | Smooth hardwood (ft²/gal) | Rough hardwood (ft²/gal) |
|---|---|---|---|---|
| Clear | 340–380 | 250–300 | 280–320 | 210–260 |
| Semi‑transparent | 260–320 | 190–240 | 220–280 | 170–220 |
| Solid / Opaque | 200–280 | 150–210 | 170–240 | 130–190 |
Porosity & roughness multipliers
| Wood type | Factor |
|---|---|
| Softwood / Pine | 1.00 |
| Cedar / Redwood | 1.10 |
| Hardwood / Ipe | 1.20 |
| Surface condition | Factor |
|---|---|
| Smooth / New | 1.00 |
| Rough‑sawn | 1.25 |
| Weathered | 1.40 |
Multiply the base coverage by method and transparency factors, then divide by these multipliers to get effective coverage.
Drying & recoat time guide
| Ambient conditions | Touch‑dry | Typical recoat window | Notes |
|---|---|---|---|
| 10–15 °C, 50–60% RH | 4–6 hours | 8–12 hours | Cool, damp air slows solvent/water evaporation. |
| 21–27 °C, 40–50% RH | 1–2 hours | 2–4 hours | Ideal range for most exterior applications. |
| 30–35 °C, 20–40% RH | 0.5–1 hour | 1–2 hours | Work in shade; watch for lap marks and flash‑off. |
Always follow product label directions; these values are planning‑grade estimates.