circuits
Ohm's Law Calculator
Enter any two independent voltage, current, resistance, or power values to solve the complete DC resistor state; extra inputs are checked for consistency.
Calculator
Formula
V = IR; P = VI = I²R = V²/R
- V — Voltage
- V · mV
- I — Current
- A · mA
- R — Resistance
- Ω · kΩ
Assumptions and limits
- Uses a positive-valued ideal DC resistive load.
Example
12 V across a 2 kΩ resistor
The calculator starts with an editable example.
Sources
Frequently asked questions
Are my inputs uploaded?
No. This calculator runs locally in your browser. Inputs are placed in a URL only when you explicitly copy a share link.
Why are units converted first?
Canonical units prevent scale errors when inputs use mixed units. The result is converted back to your selected output unit afterward.
Does the result replace professional judgment?
No. The result applies only to the stated model and assumptions. Qualified people should review high-risk engineering, medical, or laboratory decisions.