This post tells you how to choose garage door torsion springs based on door weight.
Garage door torsion springs are sized on wire diameter (d), inside diameter (D) and length of the coil (L). Eg. .250″ – 2″ – 32″ means .25″ wire, 2″ inner diameter and 32″ coil length.
Knowing which spring sizes work on your door is tricky. Many sizes actually fit and provide different lifetimes. There are color coding systems but they are still manufacturer-dependent and not completely adopted.
The tables below help you out. I have calculated the values for standard 7 ft. or 8 ft. door heights and a 4″ drum. If you have a non-standard combination, please see my Garage Door Spring Calculator.
Spring Size Chart – 7ft. height
This table lists fitting torsion springs by door weight for a 7 ft. tall garage door. The table lists weights both for a single and a dual spring configuration. Links to a spring product in Amazon are included for most sizes for convenience. (Workshoppist.com is an Amazon Associate. As an Amazon Associate we earn from qualifying purchases.)
| SPRING BY DOOR WEIGHT Door Weight (Single spring) [lb] | Door Weight (Dual springs) [lb] | (7ft door, 4in drum, 7½ t. preload) TORSION SPRING CODE [d-D-L] | Spring life [cycles] |
|---|---|---|---|
| 85 lb. | 170 lb. | .207”-2”-23” | 21k |
| 90 lb. | 180 lb. 180 lb. | .207”-2”-22” .207”-1-3/4”-25” | 17k 18k |
| 100 lb. | 195 lb. 195 lb. 205 lb. 205 lb. | .207”-2”-20” .218”-2”-26” .218”-2”-25” .225”-2”-29” | 13k 23k 19k 29k |
| 105 lb. | 210 lb. | .218”-2”-24” | 17k |
| 110 lb. | 220 lb. | .218”-2”-23” .225”-2”-27” | 14k 21k |
| 115 lb. | 230 lb. | .218”-2”-22” .225”-1-3/4”-29” | 12k 17k |
| 120 lb. | 235 lb. 240 lb. | .225”-2”-25” .218”-2”-21” | 15k 10k |
| 125 lb. | 245 lb. 245 lb. 250 lb. | .225”-2”-24” .207”-1-3/4”-18” .234”-2”-29” | 14k short 20k |
| 130 lb. | 255 lb. 260 lb. 260 lb. | .234”-2”-28” .225”-2”-23” .243”-2”-33” | 18k 12k 26k |
| 135 lb. | 265 lb. 270 lb. 270 lb. | .225”-1-3/4”-25” .225”-2”-22” .243”-2”-32” | 10k 10k 23k |
| 140 lb. | 285 lb. | .250”-2”-35” | 27k |
| 145 lb. | 285 lb. | .218”-1-3/4”-20” | short |
| 150 lb. | 300 lb. 305 lb. | .243”-2”-29” .243”-1-3/4”-32” | 16k 15k |
| 155 lb. | 310 lb. | .250”-2”-32” | 18k |
| 160 lb. | 320 lb. | .250”-2”-31” | 16k |
| 165 lb. | 330 lb. | .250”-2”-30” | 15k |
| 170 lb. | 340 lb. | .250”-2”-29” | 13k |
| 175 lb. | 350 lb. 355 lb. | .250”-1-3/4”-32” .250”-2”-28” | 12k 12k |
Use example: A typical 9×7 ft. door weighs around 100 lb. and has four spring options in the chart: .207″-2″-20″, .218″-2″-26″, .218″-2″-25″ and .225″-2″-29″. The first gives the shortest and the last the longest service life.
A wider 16×7 ft. door could weigh ~180 lb. and optimally takes a dual-spring setup to balance. The chart gives two size options: .207″-2″-22″ and .207″-1-3/4″-25″, both with a similar life. (A single-spring setup with .250″-1-3/4″-32″ or .250″-2″-28″ may just work, too.)
Spring Size Chart – 8ft. height
This table lists fitting torsion springs by door weight for a 8 ft. tall garage door. The table lists weights both for a single and a dual spring configuration.
| SPRING BY DOOR WEIGHT Door Weight (Single spring) [lb] | Door Weight (Dual springs) [lb] | (8ft door, 4in drum, 8½ t. preload) TORSION SPRING SIZE [d-D-L] | Spring life [cycles] |
|---|---|---|---|
| 95 lb. | 195 lb. | .207”-2”-23” | 13k |
| 100 lb. | 205 lb. 200 lb. | .207”-2”-22” .207”-1-3/4”-25” | 11k 12k |
| 110 lb. | 225 lb. 220 lb. | .207”-2”-20” .218”-2”-26” | 7k 14k |
| 115 lb. | 230 lb. 230 lb. | .218”-2”-25” .225”-2”-29” | 13k 17k |
| 120 lb. | 240 lb. | .218”-2”-24” | 11k |
| 125 lb. | 250 lb. | .218”-2”-23” .225”-2”-27” | 9k 13k |
| 130 lb. | 260 lb. | .218”-2”-22” .225”-1-3/4”-29” | 7k 11k |
| 135 lb. | 270 lb. 275 lb. | .225”-2”-25” .218”-2”-21” | 10k short |
| 140 lb. | 280 lb. | .225”-2”-24” .207”-1-3/4”-18” .234”-2”-29” | 8k none 13k |
| 145 lb. | 290 lb. | .234”-2”-28” .225”-2”-23” | 12k 6k |
| 150 lb. | 295 lb. 305 lb. | .243”-2”-33” .225”-1-3/4”-25” | 16k short |
| 155 lb. | 305 lb. | .225”-2”-22” .243”-2”-32” | short 14k |
| 160 lb. | 320 lb. 325 lb. | .250”-2”-35” .218”-1-3/4”-20” | 16k none |
| 170 lb. | 340 lb. 345 lb. | .243”-2”-29” .243”-1-3/4”-32” | 10k 9k |
| 175 lb. | 350 lb. | .250”-2”-32” | 12k |
| 180 lb. | 365 lb. | .250”-2”-31” | 11k |
| 190 lb. | 375 lb. | .250”-2”-30” | 9k |
| 195 lb. | 390 lb. | .250”-2”-29” | 7k |
| 200 lb. | 395 lb. 400 lb. | .250”-1-3/4”-32” .250”-2”-28” | 6k 6k |
How accurate is the weight rating?
The garage door weight should be within +-5% of the value in the tables. The pretension gives you some room for adjustment in the balance, but is only for fine-tuning.
How is spring life calculated?
The indicated spring lives in cycles are calculated using fatigue curves for the steel used in door springs. I inferred the fatigue curves (also S–N curves) from manufacturers’ spring ratings. The actual spring life will vary +- 30% around the nominal value. Please also see my post on spring wear.
Can garage door springs be too strong?
Garage door springs can be too strong (or too weak). If the springs are not matched to the door weight, they will not work: they cannot be tensioned to so that they would balance the door evenly through its travel.
Spring stiffness is what is critical, not ultimate strength. Spring stiffness, or spring rate, determines how much torque and lift the spring gives per revolution.
Can I use a heavier spring on my garage door?
You can use a heavier spring on a garage door if the spring stiffness is the same. Such springs would have the same weight rating in the table above. You can also check the IPPT (Inch-Pounds Per Revolution) specification of the springs match.
Different weight springs can (perhaps surprisingly) have the same stiffness. If a spring is both longer and made of thicker wire, it can have the same stiffness as the original.
Should I use one or two torsion springs in my garage door?
Lighter doors take one spring, heavier ones take two. If your door is 7ft. tall and under 175 lb, it can be balanced with one standard spring; if it’s above 175 lb you’ll need two. For the taller 8 ft. doors, the cutoff is at around 200 lb.
If your door weighs around 170….175 lb or 195….200 lb you can choose to use either one or two springs. Dual springs will cost you more but give a longer service life. They also reduce axial loading on the bearings.
NB. Adding a second spring to a working single-spring door never works. When going from one to two springs, you must change the type – refer to the tables above.
The options are summarized in the table below:
| NO. SPRINGS vs. DOOR WEIGHT | Weight, 7 ft. door | Weight, 8 ft. door |
|---|---|---|
| Single spring | 175 lb. or lower | 200 lb. or lower |
| Two springs | 170 lb. or higher | 195 lb. or higher |
| One/two springs | 170…175 lb. | 195…200 lb. |
