Open Sesame Garages · Oklahoma City
What size torsion spring do I need for my garage door?
A torsion spring is defined by four things: wire diameter, inside diameter, overall length, and wind direction. Together they have to match the exact weight and height of your door — there is no universal size, and a spring that is close but not correct will leave the door too heavy for the opener or drifting open on its own.
The four measurements
- Wire diameter — the thickness of the steel itself, usually between about 0.187 and 0.283 inches on residential doors. Measured by counting coils across a known length, not by eyeballing it.
- Inside diameter — the hole through the middle, commonly 1.75, 2.0, or 2.25 inches on residential doors. Usually stamped on the stationary cone.
- Length — the coiled length of the spring, not counting the cones.
- Wind direction — left-wound or right-wound. On a two-spring door you need one of each, and installing a right-wound spring on the wrong side means the door will never balance.
Why the door itself decides the answer
Springs are sized to counterbalance a specific weight lifted a specific height. Two doors that look identical from the driveway can differ by 40 pounds depending on insulation, window inserts, and material.
That is why a technician weighs or calculates the door before ordering. An insulated steel double door, a solid wood door, and a single-layer pan door of the same size all need different springs.
Door height matters too. A 7-foot door and an 8-foot door need different spring lengths even at identical weight, because the spring has to deliver its force over a longer travel.
Signs your current springs are the wrong size
- The door will not stay put when you lift it halfway by hand — it slams down (springs too weak) or rises on its own (too strong).
- The opener strains, stalls, or reverses partway up.
- The door slams the last foot instead of settling.
- Your springs fail well short of their rated cycle count, which usually means they have been working past their rating from day one.
Getting it right without measuring it yourself
Measuring an installed spring means working next to a component under high tension, and the wire diameter in particular is easy to get wrong by a hundredth of an inch — which is enough to change the spring you need.
If you want a quote, the useful details to have on hand are: door width and height, whether it is single or double, whether it is insulated, the material, and how many springs are above the door. That is usually enough for us to get close before the truck arrives.
Related questions
Can I just buy the same spring that is on the door now?
Only if the current springs are correct for the door, which is not a safe assumption — mis-sized springs are one of the most common things we find on doors that had a previous cheap repair. A spring that failed early is itself a hint that it was undersized.
Are torsion springs colour-coded?
The painted cone colour indicates wind direction, not size. It is a useful check for which side a spring goes on, and no substitute for measuring wire diameter, inside diameter, and length.
What happens if the spring is slightly too strong?
The door drifts upward on its own and does not seal at the bottom, the opener fights it on the way down, and the auto-reverse safety can behave unpredictably. Slightly too weak, and the opener carries weight it was never rated for and dies early.
Need this fixed, not just explained?
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