Pro Garage Door Spring & Conversion Calculator

Standard, high lift and vertical lift with the full cable drum catalogue. For the everyday residential job use the standard calculator.

For trade use. Drum ratings, high-lift limits and door-height limits are enforced from the manufacturer catalogue. Always confirm against the drum's own chart before ordering.

Lift Type

ft
in
lbs
Track Radius
Number of Springs
Inner Diameter
Choose the setup and press Calculate.

About this pro spring calculator

Built for garage door technicians sizing torsion springs on conversions: standard lift, high lift and vertical lift doors. Pick the lift type and cable drum, enter the door, and it lists spring options with the turns and cycle life for that drum. Drum limits are enforced, so a door that is too tall or too heavy for a drum is rejected instead of quietly miscalculated.

  • 12 cable drums from the Arrow Tru-Line catalogue, cross-referenced to APCO, Canimex, DNS and OMI part numbers.
  • High lift: the cable length includes the extra lift above the door.
  • Vertical lift: no horizontal curve, so no curve allowance in the cable.
  • Commercial wire sizes for heavy doors, with a warning when the cycle estimate goes past the fitted data.

Sizing springs for a standard home door? The spring size calculator by door weight is simpler.

Frequently Asked Questions

What is a high lift garage door conversion?

High lift track runs straight up above the door opening before it curves back, so the door travels further before it turns. The drums have to wind the extra cable, so a high lift door uses high lift drums and springs wound with more turns than a standard door of the same height.

Which cable drum do I need?

It depends on the door height, the lift type and the door weight. The calculator lists 12 drums with their maximum door height, maximum lift and weight rating, and refuses a drum the door is too big for.

Why are vertical lift results marked as estimates?

Vertical lift drums are cone shaped, so one diameter does not describe them. The calculator works from the drum's nominal diameter and says so on the result.

Why does it offer thicker wire than the other calculators?

Heavy commercial doors need wire sizes that residential springs never use. They are available here only; the cycle life of those springs is an estimate beyond the data the formula was fitted to, and the result says so.

Is the pro calculator free?

Yes, like every calculator on SpringCalc. No sign-up.