Watts, volts, amps & ohms
Watts, volts, amps & ohms: use known quantities (first / second), first quantity, second quantity. Review the formula, worked example and calculation steps.
Inputs
Use the units shown—
Enter your values and select Calculate.
Formula & explanation
V = IR; P = VI = I²R = V²/R
Variables & units
- Known quantities (first / second)
- Select an option
- First quantity
- selected unit · minimum 0.000001, maximum 1000000000000
- Second quantity
- selected unit · minimum 0.000001, maximum 1000000000000
Worked example
12 V and 2 A gives 6 Ω and 24 W.
Assumptions
Positive magnitudes for an ideal DC resistor. This is not an AC impedance or reactive-power model.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
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