Electrical calculators

Voltage drop, Ohm’s law, motor amps, kVA, derating, conduit fill and wire resistance — the arithmetic, with the code values typed from your own book. Every one works in feet and inches or in metric — flip the switch at the top and the numbers you have typed convert with it.

• Voltage drop volts & % lost over a cable run
• Ohm's law volts, amps, ohms & watts from any two
• Motor amps running current from horsepower
• kVA apparent power & amps, 1 or 3 phase
• Conductor derating corrected ampacity for heat & bundling
• Conduit fill fill % against the limit from your code book
• Wire resistance ohms of a run from size, length & resistivity
• Electricity cost kWh and running cost per day, month & year

Which one do I need?

The arithmetic of an electrical job. Anything a code sets — ampacities, fill limits, correction factors — you type from your own code book; the calculator never supplies a table value.

• Volts lost over a long run? Voltage drop calculator →
• Volts, amps, ohms or watts from two knowns? Ohm's law calculator →
• Running current of a motor? Motor amps calculator →
• Transformer or generator kVA? kVA calculator →
• How full is the conduit? Conduit fill calculator →
• Resistance of a run of wire? Wire resistance calculator →

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