Enter Your Deck Details
How the Deck Stain Calculator Works
This calculator estimates stain needed based on your deck's total surface area, including railings. It divides the area by the coverage rate of your chosen stain type, then multiplies by the number of coats. Coverage rates vary significantly between stain types — solid stains are thicker and cover less area per gallon (about 200 sq ft), while transparent sealers are thinner and cover more (up to 400 sq ft per gallon).
Choosing the Right Stain Type
Solid stains completely cover the wood grain and offer maximum UV protection. They last 4-5 years and work best on older or imperfect wood. Semi-transparent stains let some grain show through while adding color — they're the most popular choice for decks, lasting 2-3 years. Transparent sealers showcase the natural wood but provide the least protection, needing reapplication every 1-2 years. If you are coating a fence instead, use our fence stain calculator for a more accurate surface-area estimate.
Deck Staining Tips
- Always clean your deck thoroughly before staining — a pressure washer at 1,500-2,000 PSI works well
- Apply stain when temperatures are between 50-90°F with no rain expected for 24 hours
- Stain in the direction of the wood grain using a brush, roller, or pump sprayer
- Back-brush after spraying to work stain into the wood and avoid puddles
- Don't stain in direct sunlight — the stain dries too fast and won't penetrate evenly
When to Re-Stain Your Deck
A simple water test tells you when it's time: splash water on the deck. If it beads up, the stain is still protecting. If it soaks in within a few seconds, it's time to re-stain. Most decks need re-staining every 2-3 years depending on sun exposure, foot traffic, and your climate. High-traffic areas like stairs and entryways wear fastest.
Frequently Asked Questions
How many gallons of deck stain do I need?
Divide your deck's square footage by the stain's coverage rate (typically 200-400 sq ft per gallon depending on type), then multiply by the number of coats. For a 200 sq ft deck with 2 coats of semi-transparent stain (300 sq ft/gal coverage), you need about 1.3 gallons — round up to 2 gallons.
What type of deck stain lasts the longest?
Solid stain lasts the longest — typically 4-5 years before recoating. Semi-transparent stain lasts 2-3 years, and transparent sealers need reapplication every 1-2 years. Solid stains provide more UV protection and pigment, which is why they last longer, but they hide the wood grain.
How many coats of stain should I put on a deck?
Two coats is recommended for most deck stains. The first coat penetrates the wood, and the second coat builds up protection. For transparent sealers, one coat is often sufficient. Never apply more than 2 coats of solid stain — it can peel if the film gets too thick.
Should I stain a new deck right away?
No. New pressure-treated lumber is too wet to absorb stain properly. Wait 3-6 months for the wood to dry out before staining. Test readiness by sprinkling water on the deck — if it beads up, the wood isn't ready. If it soaks in, you're good to stain.
What is the coverage rate for deck stain?
Coverage varies by stain type: solid stains cover about 200 sq ft per gallon, semi-transparent stains cover 250-350 sq ft per gallon, and transparent sealers cover 300-400 sq ft per gallon. Rough or weathered wood absorbs more stain and reduces coverage by 20-30%.