Because of how they’re installed and how they move, selecting a garage door that fits your garage perfectly can be something of a challenge.
However, getting the right measurement is an important step to take in order to find a door that works well and will keep the garage dry and secure.
Taking the measurement process a step at a time can make it much simpler and will ensure a more accurate final measurement.
What is a standard garage door size?
On average, a standard two-car garage has a door that’s about 16 feet wide and 7 feet tall.
One-car garages, which are slightly less common than two-car garages, are also 7 feet tall but are only 8 or 9 feet wide.
One and two-car garages are the most common types, but three or four-car garages are also available.
You can figure out a rough estimate of any garage door’s width by using 8 feet as a base for one car space.
A three-car garage, therefore, will most likely be around 24 feet wide.
Garage door sizes vary, and even a variance of a couple of inches can make a big difference when it comes to installing a new door.
Standard sizes can give you a good approximate idea of your door options and potential cost, but it’s very important to measure carefully and take everything about your garage into account before choosing a final door.
How do I measure a garage door properly?
At first glance, you may only think about measuring the width and height of the garage door opening to figure out what size door you need.
However, there are a few other measurements to take into consideration.
- To start the measuring process, you’ll want to measure the exact width and height of the door opening.
Most door openings measure in feet, but if your door is slightly larger or smaller, be sure to include any inches or fractions of inches in your measurement. Getting as close as possible to an exact measurement will help to ensure that your door fits.
- Next, you’ll want to measure along either side of the inside of the door opening to make sure you have enough room for the track.
Depending on what type of track you want, you’ll usually need between 3.75 inches and 5.5 inches of space for the track along either side of the door.
If you’re planning on installing two doors next to each other, the post area between the two doors will need to be double whatever size track you need.
Doors that will be manually lifted or those that will use an electronic opener at the side of the door instead of on the ceiling will need even more room at each side.
Manual open or chain hoist doors can require as much as 10 inches of extra space on each side.
An electronic opener at the side can take up as much as 18 inches on that side.
- After measuring at the sides of the door, measure from the top of the door opening to the ceiling.
This area is called the headroom space.
The headroom will need to be between 10 and 12 inches tall, depending on what type of door and hardware you’re considering.
If there are lights, storage, pipes, or anything else hanging from the ceiling that won’t be moved and will be covered by the door when it’s opened, measure from the top of the door opening to the bottom of those obstructions.
- Finally, you need to measure the area known as the backroom.
The backroom is simply the depth of the garage.
Starting where the ceiling meets the wall over the door opening, measure straight back into the garage to find the backroom depth.
You will need a backroom depth that is equal to the height of the garage opening plus about 18 inches.
If you plan on installing an automatic door opener, additional hardware may need to be installed on the ceiling, and you may need even more backroom space.
Knowing how much backroom space there is can help you choose garage door equipment that will fit well.
Additional space for automatic opener equipment can be as much as 4 feet instead of 18 inches.
What else should I consider before installing or replacing a garage door?
After you’ve completed your measure, there are a few other things to take into consideration before placing an order for a door.
Taking these few extra steps can help to ensure that your final garage door fits perfectly and that installation of the door goes as smoothly as possible.
- If you’re planning to use an electronic door opener, you’ll need to make sure that the garage itself is connected to electricity.
You’ll also want to check that there’s an electrical outlet available to supply power to the opener.
Additional rewiring may be required for installing the door or installing the switch near the small door that leads out of the garage or into your house.
- You will also want to check that the floor of the garage, where the door will sit, is level.
If the floor isn’t level, you may need to repair the concrete or make adjustments.
A custom-fit door might be required in cases like this. Otherwise, the door won’t sit flush with the garage floor when it’s closed.
This can let in rain, snow, insects, or small animals, all of which can lead to damage to the items you’re storing in the garage.
- It’s also a good idea to check that the floor, ceiling, and walls are in good shape.
It’s often easier to make repairs to a garage, particularly at the ceiling, either before or during the installation of the door and its equipment.
- Additionally, you may want to check the wood or concrete at the sides of the door opening.
It’s very important to make sure that the jambs of the door are in good shape, as they’ll be holding the door in place.
If the jambs aren’t firmly and securely attached or if there are cracks or broken pieces, this can let in weather and pests.
It can also cause issues with the operation of the door, or it may cause the door itself to warp.
When you’re measuring at each step, you may want to measure in a few different areas to ensure that the measurements are all the same in each area.
For example, you may want to measure the width of the opening at the top, middle, and bottom of the door to make sure that it’s the same in each area.