How the fence paint calculation works
The calculator starts with length × average height for one broad face. It reduces panel area using the selected openness preset, adds the default gate face area, and multiplies by one or two sides. Coats and allowance determine coverage-square-feet; dividing by the product rate gives exact gallons before container rounding.
Privacy, semi-privacy, shadow-gap, and picket presets
| Fence style | Open-area assumption | Use when |
|---|---|---|
| Privacy | 0% | Boards are solid or nearly closed |
| Semi-privacy | 15% | Boards have narrow regular gaps |
| Shadow gap | 25% | Alternating boards leave visible openings |
| Picket | 40% | Pickets are clearly separated |
These presets estimate broad faces, not every board edge. For a precise bid, measure one representative section, including exposed edges, and scale it across the run.
Gate assumptions
A walk gate adds a 4 × 4 ft face and a double gate adds an 8 × 5 ft face before the one-side/two-side multiplier. Enter fence length excluding those gates. For unusual sizes, include the gate span in a separate calculation using its actual area.
Paint needed per linear foot
There is no fixed gallon-per-foot rule without height and surface design. A 6 ft solid fence has 6 sq ft of broad face per linear foot on one side and 12 sq ft on both sides, before coats and allowance. A 40%-open picket preset reduces the broad panel face to 3.6 sq ft per foot per side.
Example: 100 linear feet of 6-foot privacy fence
For a solid 100 × 6 ft privacy fence, one broad face is 600 sq ft. Coating both sides creates 1,200 sq ft of paintable area. Two coats require 2,400 coverage-square-feet; a 10% allowance raises that to 2,640. At 300 sq ft per gallon, 2,640 ÷ 300 = 8.8, so the practical purchase is 9 gallons. At $45 per gallon, material is $405, or $4.05 per linear foot, before preparation, tools, primer, and labor.
Coating one side under the same assumptions requires 4.4 gallons, rounded to 5 gallons. Change the coverage to the selected paint or stain label and reduce the broad face with the openness preset when the fence has gaps.
Paint versus stain coverage
Use the exact product's label rate. Transparent or penetrating stain may use a different method and coverage from solid-color stain or exterior paint. Rough, dry, porous, previously uncoated, or heavily weathered wood can absorb more coating.
Frequently asked questions
How much paint or stain do I need for a fence?
Multiply fence length by average height, adjust for gaps and gates, multiply by the number of coated sides and coats, add allowance, then divide by the coating's published coverage.
Should I count one side or both sides of a fence?
Count only surfaces you will actually coat. A shared fence may require both faces, while a boundary or access restriction may leave only one face in scope.
How do fence gaps affect coverage?
Open gaps reduce broad face area, but edges add some surface back. The presets are planning approximations; measure board faces and edges for unusual or high-value projects.
Can I use the calculator for both paint and stain?
Yes, provided you enter the coverage, coats, and price from the specific paint or stain product. Transparent stain, solid stain, and paint can have different application rates.
Before buying fence coating
- Inspect for rot, loose boards, contamination, and failed coating.
- Confirm cleaning, drying, sanding, and primer instructions.
- Measure both faces only when both will be coated.
- Keep material cost and installed labor quotes separate.
- Test color and absorption on a representative section.
