How Wide Should a Driveway Gate Be? Sizes for Cars, Trucks, RVs and Trailers

The wrong width is the mistake you live with every day. Too narrow and you fold a mirror every time you come home; too wide and you paid for steel you never drive through, plus a bigger opener to move it.

This guide gives the clearances that work in practice and shows how to measure so the gate you order fits the posts you have.

Clearance by vehicle

The number that matters is the clear opening: the distance between the posts, minus nothing. Your vehicle's width including mirrors is the other number. The difference is your margin, and the margin you need depends on how straight your approach is.

The "turning approach" column is the one people underestimate. If your driveway meets the street at an angle, or you have to swing wide from a narrow road, the rear wheels track inside the front wheels and the trailer cuts the corner further. Sixteen feet is the width at which most turning problems disappear.

Height and the top bar

Width gets all the attention, but the top of the gate matters for anything tall.

• A standard gate at 5 to 6 feet tall has no overhead bar, so height is only about looks and privacy.
• An arched design or a gate with a decorative top rail that spans the opening creates an overhead limit. A box truck is 12 to 13 feet; a Class A motorhome is up to 13 feet 6 inches. If an RV will ever come through, keep the drive lane open above.

Our arch and finial styles shape the top of each panel; they do not span the opening, so there is no overhead bar to hit.

Single panel or double?

Up to about 12 feet, a single swing panel is simple and cheap. Beyond that the panel gets heavy and the hinge post has to be substantial, so most gates from 12 to 20 feet are two panels meeting in the middle. Two panels also mean each one swings through a smaller arc, which helps on a short apron.

Sliding gates are always one panel, which is why they scale to 40 feet (tracked) or 60 feet (cantilever) without the hinge-load problem. If you are above 20 feet, read the swing vs. sliding guide before you decide on panels.

How to measure

Get a tape, a helper and five minutes.

1. Post to post. Measure the inside face of one post to the inside face of the other, at the height the gate will hang (usually about 3 feet up). If you have no posts yet, measure the opening you want and plan the posts outside it.
2. Measure twice, at two heights. Posts lean. If the top and bottom differ by more than half an inch, note both; the fabricator will size to the smaller.
3. Check the ground. Run the tape along the ground across the opening and note the high and low points. A cross-slope of a few inches decides swing vs. slide; see the sloped driveway guide.
4. Note what is in the swing path. Anything within 12 feet on the house side: a parked car, a garage door, a planter.
5. Photograph it. A photo from the street and one from the house, with the tape visible, catches most of what a written note misses. It is also what our chat assistant uses to give you a first estimate.

Write down the post-to-post distance. That single number, plus the height you want, is everything a fabricator needs to build the gate with the right hinge and latch clearance.

Why "sized to the inch" matters

Most gate suppliers sell stock widths: 10, 12, 14, 16 feet. Your opening is 13 feet 4 inches. So you either buy the 14 and cut the opening bigger, buy the 12 and add a filler, or pay a "custom" premium for the size you actually need.

We build every gate to the inch at the same price. That is not a marketing line; it is why our order form asks for your width and height in inches. A 160-inch gate costs what a 160-inch gate costs, and it hangs on your posts without shims or fillers.

Common width mistakes

• Sizing to the car you have rather than the truck or trailer you will own in five years. Going from 12 to 14 feet costs a little steel now and saves rebuilding the gate later.
• Forgetting the mirrors. A pickup is 6 feet 8 inches at the body and over 8 feet at the mirrors.
• Measuring the old gate. The old gate was built smaller than the opening. Measure the posts.
• Ignoring the turn. A 12-foot gate on a driveway that meets the street at 45 degrees behaves like a 9-foot gate.

If you have your post-to-post number, put it in the configurator now. The price updates for your exact width, and you can compare 12, 14 and 16 feet in a few seconds to see what the extra margin actually costs.

Related reading: Custom Size Driveway Gates: Why Sized-to-the-Inch Beats Stock, and How to Order One