Deck Refinishing Cost Calculator
Refinishing a deck is mostly labor and a few gallons of stain, but most quotes hide both inside one lump sum. This calculator separates them: it sizes the stain purchase from your wood type and the deck condition, prices prep supplies, railings and repairs as their own lines, then shows DIY, professional and a side-by-side comparison from the same inputs.
It is for an existing deck that needs cleaning, sanding and new finish. It does not price a new deck build, and its repair figures are fixed allowances, not a substitute for inspecting boards and joists in person.
Planning estimate only. Stain coverage varies by product and application method; check the coverage printed on the can. Labor rates vary by region, and the timeline is a simple hours-based estimate plus one drying day.
Quick Answer
Key takeaways
- Labor is the quote: on the worked example it is $1,620 of the $1,724 professional total, about 94%. The stain itself is $64.
- Gallons are sized, not guessed: wood type and condition set the coverage per gallon, and coats multiply the area before the count rounds up.
- The DIY figure covers stain and basic prep supplies only. Cleaner, stripper, sander or washer rental and your own weekend are not in it.
- Condition is the swing factor: the same deck in poor condition with premium product and moderate repairs prices at $4,265 in this model.
- Quick Answer
- How to use the deck refinishing cost calculator
- How the stain gallon count is sized
- Worked example: a 20 by 15 deck in professional mode
- Why condition and wood move the price so far
- The finish type setting, stated plainly
- Doing it yourself or hiring it out
- Refinish or replace: where the line sits
- What competing calculators miss
- Frequently Asked Questions
- Add This Calculator to Your Website
- References
How to use the deck refinishing cost calculator
Pick a mode first. DIY hides the labor fields and totals materials and repairs only. Professional shows the labor rate and the pressure washing option and adds labor. Compare runs both from the same inputs and prints the saving. Then enter the deck size, wood, condition, finish, quality tier and coats, add railing footage and a repair level if they apply, and press Calculate Cost.
Read the result in layers. The stain line tells you what to buy, the materials line tells you what the products cost, and the labor line, in professional mode, tells you where the quote actually goes. If a contractor quote lands far from the professional total, the gap is usually in one of three places this tool makes visible: hours, hourly rate, or a repair allowance bigger than the job needs. For a brand new build instead of a refinish, the numbers live elsewhere: the deck material calculator builds the boards, joists and footing list, and the deck cost calculator prices the whole new project.
How the stain gallon count is sized
Gallons come from coverage, and coverage comes from the wood and its condition. Each wood starts with a base coverage per gallon, then the condition adjusts it: thirsty, weathered boards get a lower effective coverage, so the same deck needs more stain.
| Wood | Base coverage (sq ft/gal) | Labor adjustment |
|---|---|---|
| Pressure-treated pine | 350 | Standard (x1.0) |
| Cedar | 300 | x1.1 |
| Redwood | 300 | x1.1 |
| Composite | 400 | x0.8 |
| Hardwood (ipe, mahogany) | 250 | x1.3 |
Condition multipliers run from 1.1 for an excellent, recently finished deck down to 0.7 for a very poor one, with supplies priced at $30 to $100 on the same scale. Those coverage figures sit inside the range manufacturers actually print: TWP lists its penetrating stains at 150 to 400 sq ft per gallon depending on the wood, with first coats at the thirsty end. Always check the can you buy, because a product at 200 sq ft per gallon will need roughly twice the gallons this model shows at 350 to 400.
Worked example: a 20 by 15 deck in professional mode
The calculator is pre-filled with this deck. Switch to the Professional tab, keep $45 an hour and washing included, and press Calculate: these are the exact figures it returns.
| Line | Result | How it got there |
|---|---|---|
| Deck area | 300 sq ft | 20 x 15 ft |
| Stain to buy | 2 gallons | ceil(300 x 2 coats / 350 coverage) |
| Finish cost | $64 | 2 gallons x $32 standard tier |
| Supplies | $40 | Good-condition allowance |
| Materials total | $104 | Finish plus supplies, no railing |
| Labor | $1,620 | 36.0 hrs (300 x 0.12) x $45 |
| Total, professional | $1,724 | Moderate $5.75 per sq ft |
| Total, DIY | $104 | Materials only, $0.35 per sq ft Budget-friendly |
| Timeline (pro mode) | 6 days | ceil(36 / 8) + 1 drying day, per the tool formula |
That split is the most useful thing on this page. Published cost guides put professional deck staining around $2 to $4 per sq ft for a straightforward job and higher for stripping or heavy prep, which brackets this $5.75 result once 36 priced hours are in it. The tool timeline deserves the same honest reading: 6 days is the raw hours formula (36 hours over 8-hour days, plus a drying day), not a promise about how a crew schedules prep, weather windows and cure time. Real jobs compress or stretch around it.
Why condition and wood move the price so far
Run the same 300 sq ft deck as a poor-condition cedar deck with premium stain, 40 ft of railing, moderate repairs and pressure washing billed extra, and the tool returns a very different job: coverage drops to 240 sq ft per gallon, so the stain count rises to 3 gallons ($150), supplies rise to $75, railing finish adds $20, repairs add $450, and labor grows to 76.0 hours, or $3,420 plus $150 for washing. The total is $4,265, or $14.22 per sq ft, rated a premium refinishing project with an 11-day tool timeline.
Nothing in that jump is arbitrary. Poor boards drink more stain, need more prep supplies and take nearly twice the labor hours per square foot of a good deck (0.20 against 0.12, before the cedar multiplier). Research from the USDA Forest Products Laboratory on deck finishing points the same way: finish service life and rework depend heavily on the wood surface and how much pigment the finish carries, with clear water repellents lasting about a year on exposed deck surfaces and semi-transparent stains lasting longest among the penetrating options. A deck that has slipped to poor condition is paying for the skipped cycles.
The finish type setting, stated plainly
In this tool, finish type names the product in your estimate but does not change the price or the coverage. Clear sealer, semi-transparent, solid stain and paint all price from the quality tier you pick: $20, $32, $50 or $70 per gallon. That is a simplification worth knowing about, because in a store the products do differ. What the setting does do is keep your result labeled correctly, so a copied estimate says what you actually plan to apply.
Choose the finish on service life and looks, then set the tier to its shelf price. Clear products show the grain and need the most frequent renewal. Semi-transparent stain is the default here because it balances grain, color and protection. Solid stain hides a patchy surface but sits more like a film. Paint on horizontal boards is the option most prone to peeling under foot traffic.
Doing it yourself or hiring it out
The saving is real and so is the work. Compare mode on the worked example puts the gap at $1,620, which is the entire labor line.
DIY refinish
- Cost on the worked example: $104 in stain and supplies
- You control prep quality, which decides how long the finish lasts
- Budget extra for cleaner, stripper and any washer or sander rental, which this tool does not price
- Expect the hours the pro estimate shows, spread over your own days: 36 hours of work is in that number
Professional refinish
- Cost on the worked example: $1,724, of which $1,620 is labor
- Crew prep, spraying equipment and product knowledge come with the quote
- Ask for the hours, rate and repair allowance in writing and compare them line by line with this estimate
- Pressure washing may be included or billed at about $0.50 per sq ft extra; the tool prices both ways
If the deck is sound and you have the time, DIY is hard to argue with on price. If boards are splintering or the old finish is failing in sheets, the labor line buys prep work that decides whether the new finish lasts one season or four. Once you have a per-square-foot figure you trust, the deck cost per square foot calculator helps you compare it against other projects priced the same way.
Refinish or replace: where the line sits
Refinish when the structure is sound: boards may be gray and worn, but they should be firm, fasteners should hold, and joists should show no soft rot. Replace, or at least get a builder to inspect, when boards are soft through, joists are compromised, or the frame moves underfoot. No finish fixes structure, and the repair allowances in this tool ($200, $450, $900) are for board-level work, not reframing.
The money points the same way on sound decks: even the heavy $4,265 scenario is far below a new build per square foot. The case for replacing is never that refinishing is expensive; it is that the deck underneath has stopped being worth finishing.
What competing calculators miss
Flat-rate refinishing estimators multiply area by a single dollar figure and call it a quote, which hides the only two decisions that matter: how much stain the wood will actually drink, and how many hours the prep will take. Lump-sum tools that do separate labor and materials rarely model condition at all, so a gray, splintering deck and a well-kept one of the same size get the same answer. The strongest rivals include stain type and coats but stop short of a DIY and professional split, and none of them show their coverage table.
This page shows its working: base coverage by wood, condition multipliers, hours per square foot by condition, wood labor adjustments, fixed repair allowances and the exact railing math (a small finish cost, a real labor cost at 0.25 hours per foot). It also states its two honest limits up front: finish type does not change the price in this model, and the DIY total excludes equipment and cleaning products beyond basic supplies.
Frequently Asked Questions
On the worked example (pressure-treated, good condition, 2 coats of standard semi-transparent stain): $104 in materials as a DIY job, or $1,724 professionally at $45 an hour, which is $5.75 per sq ft and rated a moderate cost project. Condition, product tier and repairs move the figure a long way from there.
At 350 sq ft per gallon coverage and 2 coats: ceil(300 x 2 / 350) = 2 gallons. Weathered decks and hardwood lower the coverage in the model (down to 175 sq ft per gallon for very poor hardwood), which can double the count, so check the coverage on your can before buying.
Because the timeline is a simple formula: labor hours divided by 8-hour days, rounded up, plus one drying day. The worked example has 36 labor hours, so ceil(36 / 8) + 1 = 6 days. It is a planning figure from the hours, not a schedule promise; crews, weather and cure times change real timelines.
No. Finish type labels the estimate (clear sealer, semi-transparent, solid stain or paint) but the price per gallon comes from the quality tier: $20 budget, $32 standard, $50 premium or $70 professional. Set the tier to match the shelf price of the product you actually plan to use.
Plan on every 2 to 5 years for most finishes, shorter for clear products. USDA Forest Products Laboratory research found clear water repellents last about a year on exposed deck surfaces, while pigmented semi-transparent stains give the longest service of the penetrating finishes. Sun exposure and foot traffic shorten every interval.
Yes, if you plan to refinish them. In this model railings add very little finish cost (half a gallon rate spread over each 50 ft) but real labor: 0.25 hours per linear foot in professional mode. A long railing run is mostly a labor line, not a materials line.
When the structure is failing: boards soft or rotting through, joists compromised, or a frame that flexes and moves. Refinishing restores a surface, not a structure. If the deck is sound, refinishing at single-digit dollars per sq ft is almost always far cheaper than a new build.
Because the DIY total in this tool counts stain and basic prep supplies only: $104 on a 300 sq ft deck is $0.35 per sq ft. Guides quoting $0.50 to $1.50 per sq ft for DIY usually include deck cleaner, stripper, brightener and equipment rental, which this calculator does not price. Add those before comparing the figures like for like.
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References
- USDA Forest Service, Forest Products Laboratory, "Finishing and maintaining a deck" (Forest Products Laboratory newsline, 2007) - finish service life by type, including about one year for clear water repellents and the longest service from semi-transparent stains. USDA Forest Products Laboratory: Finishing and Maintaining a Deck. Accessed October 2026.
- USDA Forest Service, Forest Products Laboratory, "Protecting Wood Decks From Biodegradation and Weathering: Evaluation of Deck Finish Systems" - multi-year exposure testing of deck finish systems, water repellency and general finish condition. USDA Forest Products Laboratory: Evaluation of Deck Finish Systems. Accessed October 2026.
- Angi, "How Much Does Deck Refinishing Cost?" - current market ranges for refinishing against replacement, and DIY against professional service costs. Angi: Deck Refinishing Cost. Accessed October 2026.
- Deck Cost Guide, "Deck Staining Cost 2026: Price per Square Foot" - planning ranges of about $2 to $4 per sq ft for professional staining and $3 to $7 or more for stripping and heavy refinishing. Deck Cost Guide: Deck Staining Cost per Square Foot. Accessed October 2026.
- TWP, "TWP 1500 Series Deck Stain" product data - manufacturer-listed coverage of 150 to 400 sq ft per gallon depending on the wood, two-coat application and dry times. TWP 1500 Series: Product and Coverage Data. Accessed October 2026.
- TWP, "TWP 100 Series Deck Stain" product data - first-coat coverage of 150 to 200 sq ft per gallon and second-coat coverage of 200 to 300 sq ft per gallon for a penetrating stain. TWP 100 Series: Product and Coverage Data. Accessed October 2026.