A gate is the part of a fence that moves, which makes it the part most likely to sag, bind or fail to latch if it is undersized for its own weight. Getting hinge and frame sizing right the first time avoids a callback to fix a gate that has dropped out of square within a season.
Frame the opening before sizing hardware
Gate posts need to be at least as sturdy as, and often sturdier than, the line posts on either side of them, since they carry the full weight of the gate on a cantilever rather than sharing load with fabric or panels the way a line post does. The fence gate calculator accounts for two dedicated gate posts per opening on top of whatever the rest of the run needs.
A gate frame itself (the structural rectangle the gate hangs from, whether built from wood, welded metal, or a manufacturer’s kit) needs diagonal bracing in most designs to resist racking, the tendency of a rectangular frame to sag into a parallelogram over time under its own weight and repeated use.
Match hinge size to gate weight and width
Light walk gates (3 to 4 feet wide, lightweight infill) can use standard residential gate hinges. Wider or heavier gates, particularly a double gate or a drive gate in the 10 to 12 foot range, need heavier-duty hinges rated for the actual weight, or the gate will sag at the latch side over time, a very common gate failure mode. If in doubt, oversize the hinge rating rather than matching it exactly to the gate’s estimated weight.
Latches
A basic gravity or slide latch is adequate for a simple walk gate. A gate that needs to be operable from both sides, or one on a pool enclosure, needs a latch designed for that specific requirement; see the next section for pool-specific rules.
Pool gates have their own requirements
Most pool safety codes require a gate that is both self-closing (a spring or gravity mechanism returns it to closed) and self-latching (it locks automatically on closing), and that swings away from the pool rather than toward it. These requirements are usually in addition to, not instead of, standard hinge and latch hardware. See pool fence code compliance and the pool fence calculator for the fuller picture, and confirm your specific local code before finalizing gate hardware.
Double gates
A double gate (two leaves meeting in the middle, common for drive access) needs a center latch or drop rod on at least one leaf to hold it in position, in addition to the hinge hardware on each outer post. Both leaves’ hinges should be sized for their individual weight, not the combined opening width.
Estimating hardware for your project
The fence gate calculator counts one hardware set (hinges plus a latch) per gate as a planning baseline; a heavy drive gate or a pool gate needs a more specific hardware plan on top of that baseline, per the notes above. Once hardware is sized, the fence cost calculator adds a gate hardware line item to your overall estimate.
Related reading: wood fence installation guide, fence cost guide.