Ohm's Law Calculator
Ohm's law calculator
Solve voltage, current, or resistance from any two known electrical values.
InputsSolve IV/A/Ohm • 6 digitsLive
Current (A)
2 A
V 12 V • I 2 A • R 6 Ohm • P 24 W
I = V / R • P = V × I
Voltage (V)
12
Current (A)
2
Resistance (Ohm)
6
Electrical power (W)
24
Advanced panelReport, LaTeX, and recent results
Calculation steps
- Step 1: Convert known values into base SI units (V, A, Ohm).
- Step 2: Apply Ohm's law (I = V / R).
- Step 3: Derive power with P = V x I.
Formula
V = I x R I = \frac{V}{R} R = \frac{V}{I} Symbol legend
| Symbol | Meaning | Unit | Copy |
|---|---|---|---|
V | Voltage | V | |
I | Current | A | |
R | Resistance | Omega |
- V is voltage in volts (V).
- I is current in amperes (A).
- R is resistance in ohms (Omega).
Example
Worked example: Solve current
- 1 Given V = 12 V and R = 6 Omega
- 2 I = V / R = 12 / 6 = 2 A
Current is 2 A.
How
- Enter any two known values among voltage, current, and resistance.
- Leave one field blank for the unknown value.
- Review the solved value as you type; results update live.
Avoid
- Entering all three values when only one should be solved.
- Using zero resistance for current calculation.
- Mixing mA with A without proper conversion.
FAQ
How many values do I need to enter?
Enter exactly two known values; the calculator solves the third.
What if I fill all three fields?
The tool will ask you to leave one field blank so it can solve a single unknown.
Can this replace full circuit analysis?
No, it solves basic V-I-R relationships only and is intended for educational use.
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