Ohm’s Law Calculator
V = IR. Free online Ohm’s Law Calculator. Calculate ohm’s law online — fast, accurate, mobile-friendly, no signup needed.
Derivation
- ├── 01Given
I = 2, R = 5 - ├── 02Formula
e.I × e.R - ├── 03Substitute
e.2 × e.5 - └── 04Compute Voltage (V)10
Georg Simon Ohm published V = I·R in 1827 but was dismissed by German universities for 15 years before his work was accepted.
Understanding the Ohm’s Law Calculator
Ohm’s Law is the foundational rule of electrical circuits: voltage equals current times resistance. It lets you find any one of those three values when you know the other two.
Physics is the toolkit for turning a real-world observation into a prediction. Whether it’s a falling object, a moving car, or a stressed beam, the equations here are the same ones every engineer relies on. The Ohm’s Law Calculator sits in that toolkit — it V = IR. Enter your numbers above and the result updates instantly; every step of the math is shown in the Derivation panel so you can see exactly how the answer was reached.
How it’s calculated
Where
- V
- Voltage (volts)
- I
- Current (amperes)
- R
- Resistance (ohms)
Step-by-step walkthrough
A circuit has 2 A current through a 5 Ω resistor.
- 01V = I × R = 2 × 5 = 10 V
- 02Power dissipated: P = V × I = 10 × 2 = 20 W
Frequently asked questions
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