Work out gate size instantly with clear inputs, formula shown and shareable results.
Leaf width is the opening less the clearances at each joint, divided by the number of leaves. A single leaf has two clearances, hinge and latch side; a double leaf has three because of the meeting stile. The diagonal brace length is the hypotenuse of the leaf, and it must run from the bottom hinge upward to work in compression.
Leaf width
Leaf = (opening - clearance x (leaves + 1)) / leaves
Brace
Brace length = sqrt(leaf width² + height²)
Leaf = (opening - clearance x (leaves + 1)) / leaves. Leaf width is the opening less the clearances at each joint, divided by the number of leaves.
From the bottom hinge corner up to the top latch corner, so it carries the sagging load in compression. Fitted the other way it works in tension and will stretch or pull its fixings.
This calculator takes 4 inputs: Structural opening width, Number of leaves, Gate height, Clearance per joint. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.