Using the Ohms Law Calculator
Enter volts and ohms, with resistance greater than zero. Current is voltage divided by resistance, while power is voltage squared divided by resistance. At a fixed resistance, doubling voltage doubles current but increases power fourfold.
Worked example
Use the example inputs below to reproduce this result. These are the form's starting values, not recommended targets. Changing your inputs updates your result above; this worked example stays fixed for comparison. Results are rounded for display.
Example inputs
- Voltage (V)
- 12
- Resistance (Ω)
- 6
Example result
- Current (A)
- 2
- Power (W)
- 24
Method and assumptions
Ohm’s law: I = V/R; P = V²/R. Assumes a resistive DC load.
Distinguish a model from a circuit specification
Electrical calculations describe the assumptions entered in the form. Real components, cables and supplies also have ratings, tolerances and operating conditions. Confirm whether the model is for DC resistance, energy over time or another specific quantity. A mathematically consistent result is not by itself a complete design or installation check.
Common question
Can I use this directly for an AC motor?
No. An AC motor is not described by a simple fixed DC resistance alone. Impedance, power factor and operating conditions matter. This tool is intended for the resistive DC model stated above.
Guide updated .