Fence Calculator

Divide your total fence length by the post spacing to get the number of sections, then add one for the final post. At 8 ft spacing a 100 ft run needs 13 sections and 14 posts. Add an extra post at every corner, end, and gate — those aren't counted automatically because they depend on your layout.

Eight feet on center is the most common spacing and matches standard 8 ft rails and panels. Drop to 6 ft for tall privacy fences, windy or exposed sites, heavy panels, or where you want extra rigidity. Closer spacing means more posts, rails, and concrete but a stronger fence.

For a solid privacy fence with no gaps, divide the fence length in inches by the picket width. A 100 ft fence (1,200 inches) of 5.5-inch boards needs about 218 pickets before waste. This calculator does the math and adds your waste percentage. Add a small gap value for a spaced picket look.

Fences up to 4 ft typically use two rails, 5–6 ft fences use three, and fences taller than 6 ft use four to keep the boards from bowing. The calculator sets rails per section from the height you choose and multiplies by the number of sections.

A 4×4 post in a 10-inch-wide, 24-inch-deep hole takes roughly two 60 lb bags of concrete. This calculator uses two bags per post as a quick estimate — for an exact bag count by hole size and post width, use our dedicated Fence Post Concrete Calculator.

Yes. Chain link switches the takeoff to linear feet of fabric and top rail plus posts; vinyl and aluminum switch to one pre-made panel per section. Wood types break down into individual pickets and rails. Just pick the material and the bill of materials updates.

Ten percent is a good default for most fences and covers cuts, corners, slopes, and the occasional warped or damaged board. Add more for very cut-up yards with lots of corners and angles, or less for a long, straight, flat run.

Yes. Open the “Measure from satellite” panel, type the property address, and trace the fence on the satellite map — click to drop each corner and drag any point to fine-tune. The tool adds up the real (geodesic) length of every run, fills in your total length, and counts each corner you trace as a post. Google can't detect a yard or lot lines automatically, so the line you draw is the measurement.

Yes, it's completely free with no signup required. Your inputs are saved locally in your browser so they persist between visits — nothing is uploaded to a server. Clearing your browser data will erase your saved values.