A sharper curve exists on the 12 inch radius and it opens lower than the 15 inch version.
Garage door track radius measure.
Anything shorter than 91 inches is a 12 track radius.
The track radius is extremely important in determining what type of springs you need for your door especially when you need to find garage door springs by weight.
Nearly all residential garage doors have a track radius of either 12 or 15.
A 12 radius has a sharper track curve and opens lower.
The amount of headroom in a garage is the determining factor between either a 12 inch or 15 inch radius.
One quick rule of thumb in finding out what you have is to measure the height of the track stopping at the bottom.
Step 1 measure the width of the opening at the widest point.
Anything between 91 93 inches is a 15 track radius.
For best results the inside of the garage door opening should be framed with 2 x 6 wood.
There are five basic garage door track options although the first two are by far the most common ones used in residential installations.