Standard Garage Door Sizes and How to Measure Your Opening
Updated November 2026 · Part of our door guides
Most residential garage doors come in a handful of standard sizes, but not every home has a standard opening, and the sizes that matter in the end are your own measurements. This guide lists the common sizes, shows how to measure the opening, headroom, side room and backroom, and explains why measuring accurately matters even more in Miami-Dade.
Planning a new door? See our replacement page. We measure on site before anything is ordered.
Standard Garage Door Sizes
| Door | Common widths | Common heights |
|---|---|---|
| Single-car | 8, 9 or 10 feet. 9 feet is the most common | 7 or 8 feet |
| Two-car | 12, 14, 16 or 18 feet. 16 feet is the standard | 7 or 8 feet |
Custom sizes exist, and older homes sometimes have openings that do not match any standard. Measure before you assume.
How to Measure Your Opening
- Measure the framed opening, not the existing door
- Measure the width from the inside of one jamb to the inside of the other, and use the narrowest reading
- Measure the height from the floor to the underside of the header
- Note anything that sticks into the opening, such as a light or a framing member
- Write down every number before you shop or call
Headroom, Side Room and Backroom
| Measurement | What it is | Typical requirement |
|---|---|---|
| Headroom | The space above the opening up to the ceiling or the lowest obstruction | About 10 to 15 inches for standard track systems. Low-headroom kits exist when space is tight |
| Side room | The space beside the opening, to the nearest wall | At least about 3¾ inches on each side for standard tracks |
| Backroom | The distance from the opening to the back wall of the garage | The door’s height plus about 18 inches |
Requirements vary by manufacturer and by the spring system, so always check the specifications for the door you choose.
Why Size Matters More in Miami-Dade
In Miami-Dade’s High Velocity Hurricane Zone, a replacement door has to be an approved product, and its Notice of Acceptance lists the largest width and height it was approved for. If your opening is larger than the approved maximum, that model cannot be used. Our permit guide shows where to find the size limits on an NOA, and our impact door page explains the testing behind it.
Common Measuring Mistakes
- Measuring the old door instead of the opening
- Rounding up or using the widest point of the jamb
- Forgetting an obstruction such as a light or beam
- Ignoring the headroom, which decides what spring system fits
- Not leaving room for the opener rail
- Assuming a door that fit a neighbor’s house will fit yours
One Wide Door or Two Single Doors?
| Option | Pros | Think about |
|---|---|---|
| One wide door | One opener, one door to maintain, and a wide opening | A failed spring or opener closes the whole opening |
| Two single doors | If one fails, the other still works, and each opening is smaller | Two openers and two sets of hardware to maintain, and a wider pier between them |
Sources
Accessed November 2026. Requirements vary by manufacturer, so check the specifications for your door.
Related Services and Guides
Frequently Asked Questions
What is the most common garage door size?
For a single-car garage, 9 feet wide and 7 feet tall. For a two-car garage, 16 feet wide and 7 feet tall.
Can I fit a bigger door in my opening?
Sometimes, if the framing allows and the door is approved for that size. Measure the opening and check the NOA before you commit.
Is the rough opening the same as the door size?
No. The framed opening is usually slightly larger than the door itself. The manufacturer lists the opening each door needs.
Do I need to measure myself?
You can, and it helps. We also measure on site before ordering, since an error means the wrong door and weeks of delay.
Planning a new door?
We measure the opening on site and check the approved sizes before anything is ordered.
Elite Miami Gardens Garage Door Repair, 6187 NW 167th St, Suite 101, Miami Gardens, FL 33015