Garage Door Spring Calculator
Determine required IPPT and winding turns for torsion springs.
Standard (400-8) – 1.9″
Standard (400-12) – 2.4″
Standard 4″ – 2.0″
1 Spring
2 Springs
Total Required IPPT:
0
IPPT Per Spring:
0
Recommended Turns:
0
Suggested Configuration:
–
⚠️ SAFETY WARNING: Garage door torsion springs are under extreme tension. Working on them without proper training and tools (like professional winding bars) can cause severe injury or death. This tool is for estimation and professional reference only.
How to Use the Garage Door Spring Calculator
When selecting a replacement torsion spring, the most critical metric is IPPT (Inch Pounds Per Turn). If you install a spring with too much IPPT, the door will fly open; if it has too little, the door will be heavy and the opener will fail prematurely.
Understanding the Core Metrics
- Door Weight: This is the dead weight of the door in its fully closed position. You can measure this using an analog scale placed under the center of the door while the springs are disconnected.
- IPPT (Inch Pounds Per Turn): This represents the amount of torque the spring provides for every full turn of the winding cone. Total IPPT must match the torque required to lift the specific weight of your door.
- Winding Turns: The number of full 360-degree rotations you must apply to the spring to counter-balance the door weight. For a standard 7-foot door, this is typically 7.5 to 8 turns.
Calculating Spring Size
To find the right spring, you need three measurements of your current spring: the wire diameter (using a 20-coil count), the inside diameter (usually 2″ or 1.75″), and the overall length of the coils. Our calculator simplifies this by working backward from the door weight and height to tell you what strength (IPPT) you actually need.
Pro-Tip: Single vs. Double Springs
If your door weighs more than 140 lbs, it is highly recommended to use a two-spring system. This distributes the load evenly across the center bracket and ensures that if one spring breaks, the other can help prevent the door from crashing down unexpectedly.