When calculating the Total Length of conduit with back-to-back 90° bends, how much gain should be considered?

When calculating the Total Length of conduit that includes back-to-back 90° bends, a gain of 2x is typically considered. This is due to the way bends affect the overall length of the conduit run.

In a typical installation, when a conduit bend is made, the physical length of the conduit increases because of the curvature, which can make the conduit longer than a straight run would be. Back-to-back bends can particularly compound this effect. The 2x gain accounts for the additional length needed to accommodate those bends effectively, ensuring that the conduit is long enough for the entire run while maintaining proper alignment and avoiding excessive strain on the conduit or the wires within.

This calculation is crucial for both practical installation and compliance with electrical codes, which often specify the maximum allowable lengths for conduit runs to ensure safety and efficiency. Properly accounting for bend gain helps prevent situations where additional lengths of conduit might be required or where installations might be at risk of failure.