Fence gate calculator
Plan the opening, the posts that carry it and the hardware a fence gate needs, for a walk gate or a double drive gate.
Fence calculator
Enter your specs. Every result updates live and shows its formula.
Overview
A gate is the one part of a fence that has to work twice a day, so the opening, the gate span and the posts that carry the hinge load are planned together, not as an afterthought to the fence run.
Walk gates commonly run 3 to 4 feet wide, drive gates 10 to 12 feet (often as a double gate), and every gate needs a properly sized post on each side because the hinge and latch posts carry load the line posts never see.
Common mistakes
- Hanging a gate on line posts sized for the fence run, when hinge and latch posts need the larger stock that carries the swinging load.
- Measuring the opening and ordering a gate panel the same width, leaving no clearance for the hinge and latch swing.
- Forgetting that wide drive openings need double gates or heavy-duty framing, not a single oversized leaf.
Related calculators
- Gate width calculator Turn your clear gate opening and hinge clearance into the gate panel width, in inches and feet, with the math shown.
- Fence cost calculator Estimate total fence cost from run length, height and your local material and labor rates, with the budget math shown.
- Privacy fence calculator Calculate posts, rails and pickets for a solid privacy fence in any material, with a zero-gap board layout by default.
Related reading
In-depth guides
Frequently asked questions
What size should a walk gate be?
A common walk gate opening is 3 to 4 feet wide, wide enough for a wheelbarrow or lawn mower at 4 feet, with a matching gate span built with side clearance so it swings free.
What size is a double drive gate?
Drive openings commonly run 10 to 12 feet wide and are built as a double gate, two leaves that meet at the middle, because a single 12 foot wood leaf gets heavy and hard on the hinge post.
What posts does a gate need?
Gate and latch posts are upsized relative to line posts, commonly a 4 by 6 or larger for wood, set deeper and in more concrete, because a swinging gate puts moments on the post the plain fence never does.
Is the gate opening the same as the gate panel size?
No: the panel is built a bit larger than the clear opening so it overlaps the gap, typically adding a small clearance figure per side. Multiply the opening by 12 with a couple of inches of total clearance to get the panel width; the gate width calculator runs that conversion.
How much clearance does a gate need to swing?
Panels commonly get a small clearance per side so the leaf swings without dragging, around an inch per side being typical. The exact figure lives in the gate width calculator if you want it turned into a panel dimension.
What hardware makes up a gate set?
Two hinges (or a hinge strap set), a latch, and the handle make the basic set, with heavier wheels or throw catches on large leaves. The gate hardware guide covers the load ratings that matter for a door that gets handled daily.
Do gate posts need concrete like every post?
Yes, and usually more of it: gate posts are set deeper in a wider hole with additional concrete because the hinge load is concentrated on them. The post concrete calculator handles the bags once you widen the hole for the gate posts.
Does the gate remove length from the fence run?
It should. A gate span is not filled with panel, so the linear run for material cuts at the gate opening, while the two gate posts stay in the post count. Getting that subtraction right is the difference between ending the project with spare boards or short a run.