How this calculator works
Painting or staining a fence is a coverage problem: you have a known surface area, and each gallon covers a published number of square feet. The calculator first multiplies length × height to get one face's area, then doubles it for both sides if you select 2, then multiplies by coats. That total surface area is divided by the product's real coverage rate — adjusted for surface texture — to give gallons per coat. A waste allowance and your product price turn that into a shopping list and a total project cost.
Total surface = Length × Height × Sides × Coats | Gallons = Total surface ÷ Coverage × (1 + Waste%)
The coverage rate is the number on the can — usually printed as "covers up to X sq ft per gallon" or "X m² per liter". We use conservative mid-range defaults by product and texture, but you should always override with the label figure if you have it in hand. A rough-sawn cedar board absorbs far more product than a planed pine board, and that difference shows up in the gallons, not the area.
Coverage rates by product and surface
These are the ranges the calculator uses by default — conservative mid-range numbers from common residential products. Always override with your product label if you have it.
| Product | Smooth (sq ft/gal) | Weathered | Rough-sawn | Typical brands |
|---|---|---|---|---|
| Exterior acrylic paint | 350 | 298 | 245 | Behr, Sherwin-Williams, Valspar |
| Solid stain | 300 | 255 | 210 | Cabot, Behr, Olympic |
| Semi-transparent stain | 250 | 213 | 175 | Cabot, Thompson's, Ready Seal |
| Clear sealer | 200 | 170 | 140 | Thompson's, Seal-Krete |
Rough-sawn and weathered boards present more surface per square foot because the grain and cracks increase total area. That is why the same gallon covers 350 sq ft on planed pine and only 245 sq ft on rough-sawn cedar — a 30% difference in material cost.
One side or both sides?
If you want the fence protected for its full life, coat both faces. One-sided coating leaves the back exposed to moisture, which is where rot and warping start on a wood fence. The calculator doubles your total area when you select 2 sides, and that number goes straight into your gallons and cost.
If you only care about curb appeal, one side is fine — but be honest about the trade-off. Interior-facing fence lines (neighbor's side) get the same weather on the untreated face.
Number of coats
Each coat adds its own full area of product. Two coats on both sides of a 100 ft fence uses roughly double the gallons of a single coat. The calculator multiplies by coats automatically, then applies your waste allowance on top.
When you actually need multiple coats:
- 2 coats — faded or weathered fences, changing color (light to dark or dark to light), new wood on the rough side, or any stain that looks thin after coat 1.
- 3 coats — severe color change (dark redwood to white), previously painted fences being stripped and recoated, or premium results on rough-sawn cedar.
- 1 coat — fresh, smooth stock in good condition being touched up with the same color, or sealer on already-sealed wood.
How much does it cost to paint a fence?
Materials only, typical 2026 US prices. Add labor at roughly 60–70% of the total for a professional job, or the labor rate shown in the calculator when you select "Professional hire".
| Product | Price / gal | 100 ft × 6 ft, 2 sides, 2 coats | Gallons | Material cost |
|---|---|---|---|---|
| Exterior paint (smooth) | $35–$55 | 2,400 sq ft surface | ≈7.5 gal | $265–$415 |
| Solid stain (weathered) | $30–$45 | 2,400 sq ft surface | ≈9.4 gal | $282–$423 |
| Semi-transparent stain (rough) | $25–$40 | 2,400 sq ft surface | ≈13.7 gal | $343–$548 |
| Clear sealer | $20–$35 | 2,400 sq ft surface | ≈13.2 gal | $264–$462 |
Pro labor typically runs $0.75–$1.50 per sq ft of coverage area for paint, less for stain, and less again for sealer. A 100 ft × 6 ft fence painted both sides, two coats, usually lands at $1,200–$2,500 total with labor.
Spray, brush, or roller?
Fence painting methods trade speed against product use and finish quality:
- Airless sprayer — fastest (about 300 sq ft per hour of coverage), but uses 15–25% more product than brush, and you must back-brush or back-roll for even penetration. Best for large, flat fences and rough-sawn stock.
- Brush only — slowest (about 100 sq ft per hour), uses the least product, and gives the deepest penetration into grain and cracks. Best for small fences, repairs, and detailed pickets.
- Roller plus brush — the practical middle ground (about 150 sq ft per hour). Roller for flat boards, brush for edges and gaps. Saves product over spray while cutting labor time in half.
The calculator shows brush/roller and sprayer times separately, so you can plan the weekend around your actual method.
Surface prep checklist
Prep decides whether your paint or stain lasts two years or eight. Skipping steps here costs more than any gallon you might save.
- Clean the surface. Scrub with a stiff brush and a mild detergent solution, or pressure-wash at under 1,500 psi. Rinse clean and let it dry 24–48 hours.
- Strip old finish if loose or peeling. A paint scraper and chemical stripper for paint; a brightener / wood restorer for stained wood that is blotchy.
- Sand rough spots. 80 grit on rough boards, 120 grit on smooth, always in the direction of the grain.
- Replace rotten boards first. Paint will not fix rot; the new finish will fail within weeks if the substrate is soft.
- Prime bare or repaired wood. Use a stain-blocking primer, not just more paint, on knots and fresh wood.
- Mask hardware and check the weather. 50–85°F (10–30°C), under 60% humidity, and no rain for 24 hours after application.
- Test a hidden panel first. One board, one coat, one day. If it dries patchy, you need a different product or more prep.
Frequently asked questions
How much paint do I need to paint a fence?
Do I need to paint both sides of my fence?
Should I spray or brush a fence?
How long does it take to paint a 100 ft fence?
Can I paint over stain?
Do I need to prime a new fence before painting?
What is better for a fence — paint or stain?
How long between coats?
How much does it cost to paint a 100 ft fence?
Will pressure-washing damage my fence before painting?
Standards and sources
Coverage rates and application guidance are compiled from typical manufacturer data sheets and residential painting practice. Key references:
- Manufacturer coverage declarations on premium exterior acrylics (typically 300–400 sq ft per gallon on smooth surfaces).
- Solid and semi-transparent stain coverage guidance (typically 250–350 sq ft per gallon).
- Wood surface prep and moisture content guidance for exterior coatings (12–15% MC before coating).
- Application temperature and humidity limits stated on product labels and technical data sheets.
Related guides
Go deeper on the questions behind this calculator.
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Estimates only. Confirm coverage, prep, and drying requirements on the product label. Check local weather and code before starting. Last reviewed October 2026.