Ohm's Law Calculator
Calculate voltage, current, or resistance using Ohm's Law.
Essential for electronics and electrical engineering.
Voltage
Current
Resistance
Ohm’s Law defines the relationship between voltage, current, and resistance in an electrical circuit:
V = I × R
Where:
- V = Voltage (Volts) — the electrical potential difference
- I = Current (Amps) — the flow of electric charge
- R = Resistance (Ohms) — opposition to current flow
Rearranged:
Current (I) = V / RResistance (R) = V / I
Power can also be derived:
P = V × I(Watts)P = I² × RP = V² / R
Common examples:
- A 60W light bulb at 120V draws 0.5 Amps
- A 12V car battery with 0.5Ω load delivers 24 Amps
- An LED with 20mA at 2V has an effective resistance of 100 Ohms