How Wide Should a Double Gate Be for a Driveway?

Start with the widest thing that drives through

A double driveway gate should be wide enough for your widest vehicle plus clearance on both sides. In practice, most US driveways work with an opening of 10 to 16 ft. Measure the vehicle's widest point, usually the mirrors, then add at least 2 ft total clearance, 1 ft per side, so the driver is not threading the gate. A single-car driveway often suits a 10 to 12 ft opening; a two-car driveway usually needs 14 to 16 ft. If a trailer, RV or delivery truck will use the gate, measure that instead. Write the opening width down before you price anything, because gate width drives post count and panel count on the rest of the run.

Fit the opening to 8 ft bays

Fence bays are commonly built at 8 ft, with posts spaced 8 ft on center. A double gate is two leaves that meet in the middle, so each leaf should be a sensible fraction of a bay. A 16 ft opening splits into two 8 ft leaves, which matches one bay per leaf. A 12 ft opening gives two 6 ft leaves, and a 10 ft opening gives two 5 ft leaves. Keep each leaf at 8 ft or less unless your supplier confirms heavier posts and hinges for the extra weight. The gate posts carry the leaf load, so they are usually larger than line posts. Ask your supplier which post size and hinge hardware they specify for your leaf width, and confirm any local permit or setback rule with your city or county building department.

Worked example: a 60 ft run with a 12 ft gate

Take a straight run of 60 ft with a 12 ft double gate. The gate leaves are 6 ft each, so the gate itself uses two leaves rather than full 8 ft bays. The remaining fence is 60 minus 12, which is 48 ft. At 8 ft post spacing, 48 ft divides into 6 bays, so you need 6 panels, 12 rails at 2 per bay, and 7 posts for that stretch, plus the 2 gate posts. That gives 9 posts total. Using the default 254 mm by 762 mm hole, about 10 in by 30 in, each hole takes roughly 0.04 m³ of concrete, so 9 holes need about 0.36 m³, or around 21 bags of 80 lb concrete at 0.017 m³ per bag. A fence calculator returns these counts directly once you enter the run length and gate width.

Why gate width changes the order

Every foot you add to the gate removes a foot from the fenced run, and that changes the panel and post count. Widen the gate from 12 ft to 16 ft on the same 60 ft run and the fence drops to 44 ft. That is 5 full bays plus 4 ft, so you need 5 panels, 10 rails and 6 line posts, plus 2 gate posts, for 8 posts total. The 16 ft gate uses two 8 ft leaves. Narrow the gate to 10 ft and the fence grows to 50 ft, which is 6 bays plus 2 ft, so you need 6 panels, 12 rails and 7 line posts, plus 2 gate posts. The calculator rounds partial bays up and adds the gate posts separately, which is why the post count moves in steps rather than smoothly.

From measurement to order list

Measure the clear opening between the gate posts, not the driveway width. Decide the leaf split, keeping each leaf at 8 ft or less. Subtract the opening from the total run to get the fenced length, divide by 8 ft for bays, and round partial bays up. Add 2 gate posts to the line post count. Multiply bays by 2 for rails. For concrete, multiply the post count by the hole volume, about 0.04 m³ for a 10 in by 30 in hole, then divide by 0.017 m³ per 80 lb bag. Enter those figures in the fence calculator to get posts, panels, rails, concrete bags, gates and a material cost. Confirm bag yield, post size and hardware with your supplier, and check permit rules with your local authority before ordering.

Frequently asked questions