Depending on the cable structure, this excess length is 0. The overlength protects the fiber in the event of bending stress or tension on the cable. Allow for. Buy a $5k fiber terminator tool so you can make custom length 🤣🤣 Coil the excess into a loop no smaller than 4-5 inches diameter and Velcro tie Gently coil and use a cable tie or velco strap to keep it neat. With both loads, the cable. A conduit fill calculator for fiber optic cable uses these rules to estimate how many cables can fit safely inside a conduit size such as 20 mm, 25 mm, 32 mm, or larger.