Ohm's law
V = I R
Electrical calculator
Ohm's Law Calculator
Enter any two known values to solve the remaining electrical quantities.
Calculator
Enter values
Results update automatically as you type.
Result
About this calculator
How it works
Ohm's law relates voltage, current, and resistance using V = I × R. Power can also be calculated using P = V × I.
Formulas
Formulas used
Power
P = V I = I^2 R = V^2 / R
Guide
How to use this calculator
- Choose the mode or component type if the calculator provides one.
- Enter known values and select the units beside each input.
- Read the highlighted result first, then use the table for supporting calculated values.
Reference
What the results mean
Voltage
Electrical potential difference.
Current
Rate of charge flow.
Resistance
Opposition to current.
Power
Electrical energy transfer rate.
FAQ
Ohm's Law Calculator questions
Can I use different units?
Yes. Select the unit beside each input. The calculator converts values internally before solving.
Are the results suitable for final design?
Use results for education, screening, and early design checks. Verify final work against standards, datasheets, and project requirements.
Why does the result update automatically?
The calculator listens for input changes and recalculates as soon as enough valid values are available.
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