Enter the number of spiral rings, the outside spiral diameter, and the inside spiral diameter into the calculator to determine the spiral length.

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## Spiral Length Formula

The following equation is used to calculate the Spiral Length.

SL = 3.14159*N*(OD+ID)/2

- Where SL is the spiral length
- N is the number of rings
- OD is the outside diameter
- ID is the inside diameter

To calculate the spiral length, multiply the number of rings by pi, then multiply by the average of the OD and ID.

The units for the OD and ID should remain the same. The result will be the spiral length in the same units.