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Electrical / Protection
Fuse Size Estimator
Estimate a current requirement and the next common nominal fuse rating.
Load requirement
Fuse estimate
Next common size20 A
20 A calculated requirement
- Duty multiplier
- 1.25×
- Calculated requirement
- 20 A
- Next listed fuse size
- 20 A
Wiring ampacity, equipment manufacturer instructions, inrush, fuse class, breaking capacity and local electrical rules override this estimate. Never uprate a fuse beyond the protected conductor or equipment rating.