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Ohm's Law Calculator (V, I, R, P Solver)

Enter any two of voltage, current, resistance and power and solve the other two. Includes unit prefixes, a running-cost estimate and the formula used for each result.

Known values (enter any two)
Running cost (optional)
Results
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voltage
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current
Notes

About Ohm's Law Calculator (V, I, R, P Solver)

The Ohm's Law Calculator solves voltage, current, resistance and power from any two known values. Units scale from millivolts to kilovolts and from milliamps to kiloamps, so small-signal and distribution work both fit.

Features

  • Enter any two of V, I, R and P
  • All four values returned
  • mV, V and kV
  • mA, A and kA
  • Ohms and watts with prefixes

How to Use

  1. Enter any two of voltage, current, resistance and power.
  2. Pick the units for each.
  3. Read the remaining two values.

Examples

Example: 120 V at 10 A -> 12.0000 ohms and 1200.0000 W.

Benefits

  • Covers every Ohm's law rearrangement in one place
  • Unit prefixes remove a common factor-of-1000 error

Frequently Asked Questions

What does this calculator do?
Enter any two of voltage, current, resistance and power and solve the other two. Includes unit prefixes, a running-cost estimate and the formula used for each result.
Is my data stored?
No. Everything runs in your browser; nothing is uploaded, saved or logged.