Deck Stain Calculator ☀️

Estimate how much stain or sealant you need for your deck project.

Deck Details

Include floorboards, railings, and steps in your total area calculation.

Rougher wood absorbs more stain.

Typically 1 for sealant, 2 for stain.

Deck Stain Coverage and Application

The most significant factor in determining stain quantity is the **porosity of the wood**. Older, rough-cut, or pressure-treated lumber will soak up significantly more material on the first coat than new, sanded decking.

Coverage Rates (Approximate First Coat)

Wood Condition Approx. Coverage (Sq Ft / US Gallon)
New, Smooth Wood200 - 300 sq ft
Average / Weathered150 - 200 sq ft
Rough, Old, or Fences100 - 150 sq ft

Application Tips

Coats and Consumption

While the first coat is fully absorbed, the **second coat** mostly sits on the surface, which is why it requires **less material (approx. 75%)** than the first. Always back-brush after spraying or rolling to ensure deep penetration.

Measuring Your Deck

Don't forget the **vertical surfaces**! Railings, balusters, and stair risers all contribute significantly to the total area. A common estimation is to **add 10-15%** to the floor area for a simple railing structure.

Important Warning: Oil-Based Stains

Rags soaked in oil-based stains and sealants can **spontaneously combust** (catch fire). Always dispose of them by soaking them in water and laying them flat to dry outside, or by sealing them in an airtight, metal container.