Ohm's Law Calculator
Find voltage, current, resistance or power from any two known values.
Inputs
Formula
- V = I × R
- P = V × I
- R = V / I
Ohm's law links voltage, current and resistance in a conductor at constant temperature. Power is the product of voltage and current.
Step-by-step calculation
- 1
Resistance
230 / 5
46 Ω
- 2
Power
230 × 5
1,150 W
Worked example
- 1230 V across a load drawing 5 A
- 2R = 230 / 5 = 46 Ω
- 3P = 230 × 5 = 1150 W
Frequently asked questions
What does the Ohm's Law Calculator do?
Find voltage, current, resistance or power from any two known values. The Ohm's Law Calculator on OneCalcApp returns the result instantly as you type, together with the formula and the substituted values.
How do I use the Ohm's Law Calculator?
Enter your values in the input fields, choose the relevant units or options, and the Ohm's Law Calculator recalculates automatically. You can copy, print or export the result.
Is the Ohm's Law Calculator free to use?
Yes. The Ohm's Law Calculator is completely free, needs no sign-up and has no usage limit on OneCalcApp.
How accurate is the Ohm's Law Calculator?
It uses the standard formula V = I × R and full double-precision arithmetic, so results match a manual calculation to the displayed number of digits.
Does the Ohm's Law Calculator work on mobile and offline?
Yes. The Ohm's Law Calculator runs entirely in your browser on phones, tablets and desktops, and your inputs never leave your device.
Where can I find related tools?
OneCalcApp hosts 300+ calculators and converters, including the full Electrical collection. Related tools are linked at the bottom of every page.
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