Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law.
Your Input
Select a calculation type, enter the known values and units, then click Calculate to see the result and step-by-step solution.
Complete User Guide
What is Ohm's Law?
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them.
How to Use
- Select a calculation type
- Enter the known values
- Select appropriate units
- Click Calculate to see the result and step-by-step solution
- Use Reset to clear and hide results
Ohm's Law Formulas
Voltage:
V = I × R
目前:
I = V / R
Resistance:
R = V / I
Power:
P = V × I
Power (alternative):
P = I² × R
Power (alternative):
P = V² / R
Calculation Types
- Voltage: Calculate voltage from current and resistance
- 目前: Calculate current from voltage and resistance
- Resistance: Calculate resistance from voltage and current
- Power: Calculate power using various formulas
Supported Units
Voltage: V, mV, kV
目前: A, mA, µA
Resistance: Ω, kΩ, MΩ, mΩ
Power: W, mW, kW, MW
Important Notes
- Voltage and current must be non-negative
- Resistance must be greater than zero
- Ohm's Law applies to linear circuits
- Results are rounded to 6 decimal places
Common Applications
- Circuit design and analysis
- Resistor selection
- Power supply calculations
- Electrical troubleshooting
- Electronics education