Wood Fence Calculator
Plan your wood fence project with accurate material estimates. Get post count, picket quantity, rail lumber, and concrete needs for your fence dimensions.
How many fence posts do I need?
Divide the total fence length by the post spacing, then add one for the end. Standard spacing is 6-8 ft for wood fences. Example: 100 ft fence ÷ 8 ft spacing = 12.5, round up to 13 + 1 end post = 14 posts total. Corner and gate posts should be larger. Line posts: 4×4 or 5×5. Corner/gate: 6×6 recommended. Deeper post holes (30-36 in) provide better stability for taller fences.
What type of wood is best for fence building?
Pressure-treated pine is most common (affordable, rot-resistant, 15-20 year lifespan). Cedar is naturally rot-resistant (more expensive, 20-30 years, splits less). Redwood is premium (beautiful grain, 25-40 years, most expensive). Pick based on: Budget (pressure-treated is cheapest), Aesthetics (cedar/redwood look better naturally), Longevity (cedar/redwood last longer without paint). Always use treated wood for posts set in concrete.
How much concrete do I need per fence post?
A standard post hole (12 in diameter × 30-36 in deep) needs about one 50-60 lb bag of fast-setting concrete mix per post. Calculate: Hole volume minus post volume. For a 4×4 post: Hole = 3.14 × (0.5 ft)² × 2.5 ft = 1.96 cu ft. Post volume = 0.33 × 0.33 × 2.5 = 0.27 cu ft. Concrete = 1.69 cu ft ≈ 1 bag. Use dry mix that sets in 20-40 minutes for faster installation.
How many pickets do I need for a privacy fence?
Divide fence length by picket width plus spacing. Standard 6 ft privacy fence: 5.5 in wide pickets with 0.5 in gap = 6 in center spacing. For 100 ft: 100 ft × 12 in / 6 in = 200 pickets. Board-on-board: 200 pickets (staggered both sides). The actual formula: Picket count = (Fence Length × 12) / (Picket Width + Gap Width). Always add 5-10% for waste.
Should I use nails or screws for fence construction?
Screws are better than nails for wood fences. Use 3-inch exterior-grade screws (coated or stainless steel) for pickets to rails. Nails (8d or 10d galvanized) are acceptable for rails to posts but may work loose over time. Screw advantages: Stronger hold, less likely to back out, easier to remove for repairs. Cost: Screws cost more but worth the investment. For high-wind areas, use structural screws.