Voltage Drop Calculator
Static · formula-only · worked example computed when this page was built · no live data
The Voltage Drop Calculator finds the percentage voltage drop on a cable run and checks it against the PEC/NEC limit. Example: for a 60 A 3-phase feeder over 45 m of 25 mm² copper cable at 400 V, Voltage drop (%) = 0.98 %, Voltage drop (V) = 3.92 V, Allowable limit = 3 % (per PEC 2017 Art. 2.10.19 | NEC 210.19).
How it works
Computed from your inputs per PEC 2017 Art. 2.10.19 | NEC 210.19. Anything the worked example does not state uses this calculator's standard default; the interactive version shows every input and lets you change it.
Worked example (Electrical & Power)
Inputs: a 60 A 3-phase feeder over 45 m of 25 mm² copper cable at 400 V.
| Result | Value |
|---|---|
| Voltage drop (%) | 0.98 % |
| Voltage drop (V) | 3.92 V |
| Allowable limit | 3 % |
Computed by WorkHive's calculation engine when this page was built; standard: PEC 2017 Art. 2.10.19 | NEC 210.19.
How to use this calculator
- Read the worked example. It uses a 60 A 3-phase feeder over 45 m of 25 mm² copper cable at 400 V and shows every number in the method.
- Follow the formula with your own figures: it returns Voltage drop, Drop, Limit, computed per PEC 2017 Art. 2.10.19 | NEC 210.19.
- To compute interactively, open the Voltage Drop Calculator inside WorkHive's free Engineering Design suite (link below). It runs the same method with your inputs.
FAQ
What is a voltage drop calculator cable PEC?
The Voltage Drop Calculator is a free online tool that finds the percentage voltage drop on a cable run and checks it against the PEC/NEC limit. It shows the formula and a fully worked example so you can check the method, not just the number.
How is it calculated?
The result is computed from your inputs following PEC 2017 Art. 2.10.19 | NEC 210.19. The worked example on this page shows a real computation with real numbers.
Is the calculator free?
Yes. WorkHive is free: this worked example is open to everyone, and the interactive calculator runs inside the free Engineering Design suite after a free sign-up (your work is saved to your account). WorkHive is a free, offline-first maintenance platform built for Philippine industrial plants.
Run it on your own numbers
Open the interactive Voltage Drop Calculator in WorkHive. Free, and a free sign-up saves your calculations, BOMs and scope-of-works to your account.