About the Voltage Calculator
Voltage from current and resistance (V = IR) — solve for any of the three values.
Also known as: volts calculator, find voltage, v = ir, potential difference.
How to use this calculator
- Enter solve for.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
V = I × R
Worked example
Using the values pre-filled in the calculator above:
- Solve for: Voltage
- Current = 3 A
- Resistance = 8 Ω
the calculator returns:
- Voltage: 24 V
- Current: 3 A
- Resistance: 8 Ω