Free Ohms Law Calculator - Electrical Made Easy
Calculate voltage, current, resistance, and power using Ohm's Law. Essential for electrical engineering, electronics, and circuit design.
Quick Answer
Ohms Law: V = I × R. Power: P = V × I. Example: 120V with 10Ω resistance = 12 amps current and 1,440 watts power.
Key Facts about Ohms Law Calculator:
- V = I × R (voltage = current × resistance)
- P = V × I (power = voltage × current)
- Also: P = I²R and P = V²/R
- 1 amp through 1 ohm = 1 volt
- Measured in volts, amps, ohms, watts
Why Use Our Ohms Law Calculator?
Complete electrical calculations:
Ohms Law
V = I × R calculations.
Power
P = V × I calculations.
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How to Ohms Law Calculator in 3 Easy Steps
Calculate circuits:
Enter Known Values
Any two of V, I, R, P.
Select Unknown
What to calculate.
Get Result
See calculated value.
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Frequently Asked Questions
Everything you need to know about our ohms law calculator
What is Ohms Law?
V = I × R (Voltage = Current × Resistance)
Ohms Law states V = I × R (Voltage = Current × Resistance). Related: I = V/R, R = V/I. Power: P = V × I = I²R = V²/R.
How do I calculate power in a circuit?
P = V × I (e.g., 12V × 2A = 24W)
Power (watts) = Voltage × Current (P = VI). Also P = I²R or P = V²/R. A 12V circuit with 2A current: P = 12 × 2 = 24 watts.
What units does Ohms Law use?
V = volts, I = amps, R = ohms, P = watts
Voltage in volts (V), current in amperes/amps (A), resistance in ohms (Ω), power in watts (W). 1 volt across 1 ohm produces 1 amp.
Still have questions? Try the tool yourself!
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