Measure the torsion springs you already have, work out the spring rate, and find the replacement size that will actually balance your door. Wire size, DASMA color code, winding turns and the full size chart, all on one page.
Measure the spring while it is unwound and off the door. Wire size is the only measurement people get wrong, so measure across 20 coils, not one.
Weigh the door first. With the springs unwound and the cables off, lift the closed door onto a bathroom scale and read it. Guessing the weight is the fastest way to get the wrong spring.
Standard residential setup with 400-8 cable drums. One turn equals one full 360 degree revolution, which is four quarter turns on the winding bars.
| Door height | Full turns | Quarter turns |
|---|
These are starting points. Finish by testing the balance: the door should hold still when stopped halfway, and drift no more than a couple of inches.
How to read your spring
Four numbers describe every torsion spring, and you need all four to order a replacement: wire size, inside diameter, length, and wind direction. Get any one of them wrong and the door will not balance.
Wind direction. On a standard residential door the spring on the left side of the center bracket is right wound and usually has a red winding cone. The one on the right is left wound with a black cone. If your springs are painted, look at which way the last coil points when the spring lies flat.
Garage door torsion spring wire size chart
Measure 20 coils and divide by 20. The DASMA color is painted on the spring or on the cone, but paint fades and gets overwritten, so trust the measurement over the color.
| 20 coils measure | Wire size | DASMA color |
|---|
Typical door weights
Use this only to sanity check a reading. Insulation, glass, hardware and old paint move these numbers a lot, and a wood or carriage door can be double what you expect.
| Door | Construction | Typical weight |
|---|---|---|
| 8 x 7 single | Steel, non insulated | 90 to 110 lbs |
| 9 x 7 single | Steel, non insulated | 100 to 125 lbs |
| 9 x 7 single | Steel, insulated | 130 to 160 lbs |
| 16 x 7 double | Steel, non insulated | 140 to 170 lbs |
| 16 x 7 double | Steel, insulated | 190 to 230 lbs |
| 16 x 7 double | Wood or carriage house | 250 to 350 lbs |
Rather not gamble on it?
We replace torsion springs across Spring, The Woodlands, Conroe and Humble, usually the same day. We carry the common sizes on the truck.
Call (832) 702-5376Common questions
What size torsion spring do I need for a 16×7 garage door?
There is no single answer, because width does not set the spring, weight does. Two 16×7 doors can differ by 100 lbs depending on insulation and material. Weigh the door, then use the calculator above.
How many turns on a 7 ft garage door spring?
Seven and a half full turns, which is 30 quarter turns on the bars. The rule of thumb is the door height in feet plus half a turn.
How do I know what size spring I have?
Measure 20 coils and divide by 20 to get wire size, read the cone stamp or measure the inside diameter, and measure the coils end to end for length. The calculator above turns those three numbers into the spring rate.
Can I put a heavier spring on my door?
Only if the math supports it. An overpowered spring makes the door fly open, stresses the opener and can pull the top section apart. A spring that is too light strains the opener and lets the door slam.
How long do torsion springs last?
Standard springs are rated around 10,000 cycles, which is roughly seven years at four openings a day. High cycle springs run 25,000 or more.
Spring rate is calculated with the accepted industry formula IPPT = (E x d⁴) / (10.8 x Dm x Na), using E = 28,500,000 psi for oil tempered spring steel, and a 400-8 cable drum with a 1.84 in effective radius. Results are engineering estimates for reference and do not replace inspection by a qualified technician.