Spring Calculator

I have a spring — what does it lift?

Measure the spring you've got (wire, inside dia, length) and we'll tell you the door weight it can counterbalance — and suggest longer-life replacements.

I have a door — what spring do I need?

Tell us about the door (weight + height + drum) and we'll rank the spring options, sorted by cycle life. Don't know the door weight? We'll help estimate.

I have a spring — find a matching replacement

Enter the spring you're replacing and get an equivalent with matching lift (IPPT). Handles mismatched duplex pairs too.

Does my current spring fit my door?

Already have a door and spring installed? We'll compare the two and flag if the spring is over- or under-sized for the door.