Deck Stain Calculator
Solid Stain (150-200 sq ft)
Semi-Transparent (200-300 sq ft)
Clear Sealer (300-400 sq ft)
1 Coat
2 Coats
Estimation Results
Surface Area (Flat):
0 sq ft
Total Coverage Area (Inc. Coats/Railings):
0 sq ft
Total Stain Needed:
0 Gallons
*Always round up to the nearest whole gallon to ensure you don't run out mid-project.
How to Calculate Deck Stain Coverage
Planning a deck restoration project requires precision. Use this deck stain calculator to estimate exactly how much product you need to purchase. Most DIYers either buy too much or, worse, run out when the wood is half-finished, leading to uneven lap marks.
The Formula for Success
To calculate the amount of stain needed, we use the following math:
- Base Area: Length × Width = Square Footage.
- Railing Factor: Railings and spindles have a high surface area. We add roughly 25-30% to the total square footage to account for these vertical surfaces.
- Coat Multiplier: Most semi-transparent and solid stains require two coats for maximum protection and color depth.
- Absorption Rate: New, dry wood absorbs significantly more stain than older, previously treated wood.
How Much Area Does One Gallon Cover?
Stain coverage varies wildly based on the type of product:
- Solid Stains: 150 – 200 sq. ft. per gallon (thicker, like paint).
- Semi-Transparent Stains: 250 – 350 sq. ft. per gallon.
- Clear Sealers: 300 – 400 sq. ft. per gallon.
Professional Tips for Staining
Check the Weather: Ensure there is no rain in the forecast for at least 24 to 48 hours after application. Ideal temperatures are between 50°F and 90°F.
Prep is Key: Always clean your deck with a specialized wood cleaner and let it dry completely (usually 48 hours) before applying stain. Moisture trapped in the wood will cause the stain to peel.
The "Splash Test": If you aren't sure if your deck needs staining, drop some water on it. If the water beads up, the old sealer is still working. If it soaks in immediately, it's time to restain.