Text & Web Utilities
Ohm's Law Calculator
Solve voltage, current, resistance, and power.
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About the Ohm's Law Calculator
Ohm's Law relates voltage, current, and resistance: V = I × R. Enter any two values (leave the unknown at 0) and the calculator solves for the third and also computes power (P = V × I). It's the fundamental tool for electronics, circuit design, and electrical work.
How to use the Ohm's Law Calculator
- 01Enter your any two of voltage, current, and resistance.
- 02Read the result instantly — it recalculates as you type.
- 03Adjust the numbers to model different scenarios.
Frequently asked questions
What is Ohm's Law?
V = I × R — voltage equals current times resistance. Rearranged, I = V ÷ R and R = V ÷ I. This tool solves for whichever value you leave blank.
How do I calculate power?
Power = voltage × current (P = V × I), also equal to I²R or V²/R. The calculator shows power alongside the missing value.