Measure length × width of your deck surface
Total length of railing (adds ~4 sq ft per linear foot for balusters, both sides, and top)
Recommended: 2 coats for semi-transparent
Needed when removing old stain before re-staining. Not required for new wood.
Opens wood pores and restores pH after stripping or pressure washing. Improves stain absorption.
Gallons of Stain Needed
4 gallons
Semi-Transparent - 2 coats over 300 sq ft
Stain Quantity
Buying Options
5-gallon buckets save 10-15% per gallon versus singles. Check your local big-box store or stain manufacturer site for current pricing.
Cost Estimate
Prices are 2026 retail estimates. Premium brands like TWP, Cabot, and Armstrong Clark run at the higher end. Store brands and sales bring costs down.
12,800+ estimates calculated this month
Last updated: 2026-03-17
How Much Stain Does a Deck Actually Need?
The short answer: more than you think. I've re-stained decks where the homeowner bought "exactly the right amount" based on the can label and ran out with a quarter of the deck left to go. The coverage numbers on the can assume smooth, new wood and perfect conditions. Real decks rarely cooperate.
Weathered boards soak up stain like a sponge. End grain on cut boards absorbs even more. Gaps between boards waste product. And if you are brushing, you are working stain into cracks and grain patterns that the coverage spec doesn't account for.
Use our deck stain calculator above to get a realistic number, then round up. Running back to the store mid-job is a waste of your Saturday. Try EstimationPro free to build complete deck estimates with labor, materials, and stain costs in minutes.
Deck Stain Coverage by Type
| Stain Type | Coverage/Gal | Price/Gal | Durability | Grain Visibility |
|---|---|---|---|---|
| Transparent | ~250 sq ft | $30-$50 | 1-2 years | Full grain visible |
| Semi-Transparent | ~200 sq ft | $35-$55 | 2-3 years | Grain shows through |
| Semi-Solid | ~175 sq ft | $38-$60 | 3-4 years | Partial grain visible |
| Solid | ~150 sq ft | $40-$65 | 4-5 years | No grain (paint-like) |
Coverage is per coat on smooth new wood. Rough or weathered surfaces reduce coverage 15-25%.
Worked Examples
Example A: 12×20 deck (240 sq ft), new cedar, semi-transparent, brush application
- Coverage: 200 sq ft/gal × 1.0 (new wood) = 200 sq ft/gal
- Two coats: 240 × 2 = 480 sq ft total
- 480 / 200 = 2.4 gal + 5% brush waste = 2.52 gal
- Round up: 3 gallons
- Cost: $105-$165 for stain
Example B: 16×24 deck (384 sq ft) + 60 LF railing, weathered wood, semi-transparent, roller
- Railing: 60 LF × 4 = 240 sq ft. Total: 384 + 240 = 624 sq ft
- Coverage: 200 × 0.75 (weathered) = 150 sq ft/gal
- Two coats: 624 × 2 = 1,248 sq ft total
- 1,248 / 150 = 8.32 gal + 10% roller waste = 9.15 gal
- Round up: 10 gallons (2 × 5-gal buckets)
- Cost: $350-$550 for stain, plus $175 for stripper and $50 for brightener
Example C: Small 8×10 entry deck (80 sq ft), pressure-treated, solid stain, brush
- Coverage: 150 × 0.85 (PT wood) = 127.5 sq ft/gal
- Two coats: 80 × 2 = 160 sq ft total
- 160 / 127.5 = 1.25 gal + 5% waste = 1.32 gal
- Round up: 2 gallons
- Cost: $80-$130 for stain
Prep Work Makes or Breaks the Finish
I've seen homeowners spend $200 on premium stain and slap it on a dirty, gray deck without any prep. Three months later it's peeling. Stain can only bond to clean, dry wood. If the surface isn't right, nothing you put on top will stick.
- Pressure wash first. Always. Use a fan tip at 1,500-2,000 PSI for softwood decks (cedar, pine, PT). Going over 2,500 PSI on softwood damages the fibers and creates a fuzzy surface that doesn't stain evenly.
- Strip old stain when it's failing. If the old stain is peeling, flaking, or the deck has 3+ coats of buildup, strip it down. Stain stripper runs about $25/gal and covers 100 sq ft. Apply, wait 15-30 minutes, pressure wash off.
- Brighten after stripping. Strippers are alkaline. Wood brightener (oxalic acid) restores the pH and opens pores. $15/gal, 200 sq ft coverage. This step takes 20 minutes and makes a visible difference in how evenly the stain absorbs.
- Let the deck dry completely. After washing, wait at least 48 hours with good weather before staining. Moisture trapped under the stain causes adhesion failure. Check the forecast before you start prep.
Common Deck Staining Mistakes
- Staining in direct sunlight. The stain dries too fast before it can penetrate. You get a thin film on top that peels within weeks. Start on the shaded side, or stain in the morning or late afternoon.
- Applying too thick. More is not better with deck stain. Two thin coats penetrate and bond. One thick coat sits on top and peels. Apply the first coat, let it soak in for 15-20 minutes, then wipe up any puddles before the second coat.
- Ignoring the end grain. Cut ends of boards absorb 5-10x more stain than face grain. Pre-seal cut ends before your main application, or plan to apply extra stain to those spots.
- Not back-brushing after spraying. Spraying gets stain on the surface. Back-brushing works it into the wood. If you spray and walk away, you get a surface coating instead of a penetrating stain. That coating peels.
- Staining pressure-treated wood too soon. New PT lumber is soaked in preservative. Give it 3-6 months to dry out, or the stain won't absorb. Water bead test: if water beads up on the surface, it's not ready.
Stain Cost per Square Foot
| Stain Type | Material $/sq ft | With Pro Labor | 300 sq ft Deck Total |
|---|---|---|---|
| Transparent | $0.24-$0.40 | $2.00-$3.50 | $600-$1,050 |
| Semi-Transparent | $0.35-$0.55 | $2.50-$4.00 | $750-$1,200 |
| Semi-Solid | $0.43-$0.69 | $2.75-$4.50 | $825-$1,350 |
| Solid | $0.53-$0.87 | $3.00-$5.00 | $900-$1,500 |
Material costs assume 2 coats on smooth new wood. Pro labor includes pressure washing and prep. Prices vary by region.
Need to estimate a full deck build or refinishing project? Our deck cost calculator covers framing, decking, and labor. For measuring your deck area, the square footage calculator handles any shape. And if you're building a complete estimate with materials, labor, and profit margin, EstimationPro puts the whole thing together into a professional proposal. It doesn't just build the estimate - it sends the proposal automatically and follows up with the homeowner so you win more of the bids you already send. Try EstimationPro free.
How to Use This Calculator
Pick your stain type
Choose transparent, semi-transparent, semi-solid, or solid color. Each has different coverage rates, durability, and pricing. Semi-transparent is the most popular choice for decks.
Select your wood condition
New wood gets the best coverage. Weathered, rough wood absorbs more stain and needs 25% or more extra material. Previously stained decks fall somewhere in between.
Measure your deck area
Multiply deck length by width for the floor. Add railing linear footage separately. The calculator converts railing to square footage automatically (about 4 sq ft per linear foot for balusters and top rail).
Set coats and review results
Two coats is standard for most stain types. The calculator shows gallons needed, buying options, and material cost estimates including optional prep products like stripper and brightener.
Deck Stain Quantity Formula
Adjusted Coverage = Base Coverage (sq ft/gal) × Wood Condition Factor
Total Area = Deck Floor + (Railing LF × 4)
Gallons = (Total Area × Coats) ÷ Adjusted Coverage × (1 + Application Waste%)
Total Cost = Gallons × Price per Gallon + Prep ProductsWhere:
- Base Coverage
- = 150-250 sq ft/gal depending on stain type (transparent to solid)
- Wood Condition Factor
- = 1.0 for new wood, down to 0.75 for weathered surfaces
- Coats
- = Number of coats (typically 2)
- Application Waste
- = 5% brush, 8% pad, 10% roller, 20% sprayer
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Frequently Asked Questions
How much deck stain do I need per square foot?
It depends on the stain type. Transparent stains cover about 250 sq ft per gallon, semi-transparent covers about 200 sq ft/gal, semi-solid about 175 sq ft/gal, and solid stain about 150 sq ft/gal. These are per-coat numbers on smooth, new wood. Rough or weathered wood reduces coverage by 15-25%. Two coats doubles your usage.
How many gallons of stain for a 300 sq ft deck?
Using semi-transparent stain on new wood with 2 coats: 300 × 2 / 200 = 3 gallons. Add 5-10% for waste depending on your application method. If you have railings, add their square footage too. Budget 3-4 gallons total. On weathered wood, you might need closer to 5 gallons because the rough surface absorbs more.
Should I use transparent, semi-transparent, or solid deck stain?
Semi-transparent is the go-to for most decks. It shows the wood grain while adding color and UV protection, and it lasts 2-3 years before needing a refresh. Transparent stain looks beautiful but only lasts 1-2 years and offers minimal UV protection. Solid stain gives the most protection (4-5 years) but hides the grain entirely and can peel on horizontal deck surfaces where water pools.
Do I need to strip old stain before re-staining?
Not always. If your existing stain is the same type and in decent shape, you can clean the deck and recoat directly. You must strip first when: switching from solid to semi-transparent, the old stain is peeling or flaking, or there is heavy buildup from multiple coats over the years. Stripping costs about $25/gal and covers 100 sq ft. Budget the extra material and an extra day of work.
How long does deck stain last?
Lifespan varies by stain type and exposure: Transparent: 1-2 years. Semi-transparent: 2-3 years. Semi-solid: 3-4 years. Solid: 4-5 years. South-facing decks with full sun exposure wear fastest. Decks under a covered porch last longer. Proper prep and 2 full coats give you the best longevity regardless of type.
Can I stain pressure-treated wood?
Yes, but wait until it dries. New pressure-treated lumber is saturated with preservative and water. It needs 3-6 months to dry before stain will absorb properly. Test by sprinkling water on the surface. If it beads up, the wood is not ready. If it soaks in, you are good to go. Once dry, pressure-treated wood accepts stain well but absorbs about 15% more than kiln-dried lumber.
What is the best way to apply deck stain?
Brush gives the best results. The bristles work stain into the wood grain for better penetration and a more even finish. A stain pad or applicator is a good middle ground for speed and quality on flat deck boards. Sprayer with back-brushing is fastest for large decks but wastes 15-20% more stain from overspray. Use a brush for railings regardless of what you use on the floor.
How much does it cost to stain a deck?
Materials only, a typical 300 sq ft deck costs $105-$220 in stain (2 coats, semi-transparent). Add prep products and you are looking at $150-$300 total materials. Hiring a pro runs $2-$5 per sq ft for labor on top of materials, so a 300 sq ft deck runs $750-$1,800 total with a contractor. DIY saves the labor cost but takes a full weekend.
Do I need wood brightener after stripping?
Yes, strongly recommended. Stain strippers are alkaline and raise the wood pH, which can cause stain adhesion problems and blotchy results. Wood brightener (oxalic acid based) restores the pH, opens pores, and gives you a clean surface for even stain absorption. It costs about $15/gal and covers 200 sq ft. Skipping it to save $15-$30 risks a bad finish on a $200+ stain job.
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