When determining spring size the height and weight of the garage door are very important. Failure to
use the proper size spring will lead to an unbalanced garage door. An unbalanced garage door will cause
other serious issues like premature failure of garage door components and damage to or failure of the
automatic garage door opener. An unbalanced garage door could be a door that is very heavy to open,
this can be a dangerous situation as the garage door may not open properly or remain in the open
position. When a garage door is very heavy the door could fall to the ground damaging anything under
the door, injuring or killing a person or animal and even damaging the door itself. A heavy garage door
also puts added stress on the automatic garage door opener because the opener is now having to lift
more weight than it is designed to lift. In this case the spring(s) are not of the proper strength rating to
lift the garage door or it could be the spring does not have the proper number of winds. The other type
of unbalanced garage door issue is a garage door that is too hot, meaning the door flies open. This is
dangerous as well and can damage the garage door or other garage door components, the automatic
garage door opener and there is a risk that the door will fly open too far and the door can come off
track. In this case the garage door spring is too strong for the garage door it is lifting or the spring(s)
have too many winds.
Garage door balance is the single most important thing we test on a garage door. If a garage door is not
well balanced, the door will not function properly and will cause failure to other components of the
garage door and automatic garage door opener.
The weight of the garage door is important because we use the weight of the door to calculate the IPPT
(inch per pound turn). We then use the IPPT to determine the proper spring or springs to use on the
For a 7’ garage door weighing 185 pounds I would recommend using a 262x2x32 spring if you want a
one spring system.
If you prefer a two spring system for the same 7’ garage door weighing 185 pounds I would recommend
two 225x2x30 springs.
These spring sizes are only recommendations and there are many other springs or combinations of
springs that are rated for a garage door weighing 185 pounds. The most important thing is selecting a
spring or combination of springs that is rated for a 185 pound garage door.
The height of the garage door is important to know because it affects the number of winds the spring or
springs will need. For a 7’ foot tall garage door you should put 29 quarter turns on each spring. The
height of the garage door can also affect the size of the spring or spring combination needed as well.
When replacing garage door springs we always weigh the garage door and figure the IPPT to ensure we
always use the proper spring(s) for the garage door. 10 pounds may not seem like much weight, but for
a garage door spring, just a few pounds makes a significant difference.