Ohm's Law Power Calculator

Your details

Choose which two quantities to solve for. Supply the other two as inputs.
Electrical power in watts (or your chosen prefix).
Electrical resistance in ohms (or your chosen prefix).
Voltage (V)
100.0 V

Electric potential difference

Current (I)1.000 A
Resistance (R)100.0 ohm
Power (P)100.0 W
Voltage (V, SI)100
Current (A, SI)1
Resistance (ohm, SI)100
Power (W, SI)100
Voltage (V)100
Current (A)1
Power (W)100

Voltage: 100.0 V | Current: 1.000 A | Resistance: 100.0 ohm | Power: 100.0 W

  • At 100.0 V, this is a mains-level or higher voltage. Use proper insulation and isolation.
  • Power dissipation is 100.0 W. At this level, heat management (heatsinking) is likely needed.
  • Current of 1.000 A is above 1 A. Verify wire gauge and connector ratings can handle this level continuously.
  • These calculations apply to purely resistive DC circuits. For AC circuits, use impedance (Z) in place of resistance and note that reactive components affect phase and apparent power.

Next stepDouble-check component power ratings (resistors, MOSFETs, transistors) against the computed power value. Always apply a derating factor of at least 50% for long-term reliability.

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