Ohm's Law Current Calculator

Calculate electric current from voltage and resistance using Ohm's law (I = V / R).

Inputs

Voltage (V)

Resistance (Ω)

Tab to move between fields

Results

Current (A)

Power (W)36

How to Use This Calculator

Start by filling in the input fields below. Results update instantly as you type, so you can experiment with different values to see how they affect the outcome.
Voltage (V) — enter a numeric value. Minimum value: 0 (default: 12).
Resistance (Ω) — enter a numeric value. Minimum value: 0.0001 (default: 4).
Once all inputs are set, review your results in the Results panel. Here's what each output means:
Current (A) — shown as a numeric value. This is the primary result of this calculator.
Power (W) — shown as a numeric value.

How the result changes with Resistance (Ω)

Resistance (Ω)	Current (A)
1.6	7.5
5.6	2.143
10	1.2
14	0.857

How this is calculated

Worked example, using the default values

current
voltage / resistance
voltage / resistance = 3
power
voltage * current
voltage * current = 36

Engine last updated July 9, 2026. Checked against 3 independently-derived tests — how we verify calculators.

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