Guide
What size garage door do you need for two cars?
The honest answer depends on what you drive, not on how many cars you own. Two compacts and two full-size pickups are four feet apart in what they need.
Sixteen feet is the common answer and it is only the right answer if you drive normal cars. What actually decides it is the width of your two vehicles across the mirrors, plus the room to open a door.
A 16x7, drawn to scale. Two normal cars side by side. The most common double door in America.
In full
Two cars need more than the sum of two cars. A mid-size saloon is around six feet across the body but closer to seven across the mirrors, and a car door swings about two feet six. So the calculation is not "will they both fit through" — it is "will both people get out once they are in", and the second question is the one people answer wrong.
Sixteen feet is eight feet a car. That works comfortably for two ordinary cars and it is why 16x7 became the default double. Two full-size pickups is where it stops working: the bodies clear, but the mirrors do not leave room for the angle you have to take lining up on the second one, and somebody ends up parking one of them outside.
Eighteen feet is nine feet a car and it is the size that makes two large vehicles genuinely comfortable. It is common on newer builds for exactly that reason. Twenty feet is generous for two and is usually specified when the garage is doing something else as well — a workbench down one wall, a trailer beside the car.
There is a second decision hiding inside the first one: one wide door or two singles. Two 9x7 doors in a two-car garage means a supporting pier between them, which is structurally simpler and cheaper to build, and it means a broken spring only takes one car out of action. One 16-foot door means no pier, easier manoeuvring, and a single point of failure. Neither is wrong. Builders mostly choose the single wide door because it looks better from the street.
Height matters as much as width if either vehicle is tall. Going from 16x7 to 16x8 buys nothing at all in parking comfort — it is the same width — and buys everything if one of the cars has a roof rack. If the problem is doors and mirrors, the answer is eighteen feet wide. If the problem is the roof, the answer is eight feet high. They are different problems and the same-sounding upgrade does not solve both.
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