Ohm's Law Calculator
Calculate voltage, current, or resistance using Ohm's law. Enter any two values to find the third, plus power output.
How to Use the Ohm's Law Calculator
- Enter the known physical values in the corresponding fields.
- Select the appropriate units if multiple options are available.
- The unknown value is computed instantly from the formula.
- Review the result and the formula explanation below.
クイックリファレンス
| 変換元 | 変換先 |
|---|---|
| V = 12, R = 4 | I = 3 A |
| V = 220, R = 100 | I = 2.2 A |
| I = 2, R = 10 | V = 20 V |
| V = 5, I = 0.5 | R = 10 Ω |
| P = 100 W, V = 220 | I ≈ 0.45 A |
| V = 9, R = 3 | I = 3 A |
使用例
- •Solving physics homework or exam problems with the correct formula.
- •Verifying experimental measurements and calculations in the lab.
- •Understanding physical relationships between quantities.
- •Quick engineering calculations for design or estimation.
計算式
V = I × R. Current: I = V / R. Resistance: R = V / I. Power: P = V × I.
よくある質問
What is Ohm's law?
Ohm's law states that voltage equals current times resistance: V = I × R. It relates the three fundamental electrical quantities.
How do I find current from voltage and resistance?
Divide voltage by resistance: I = V / R. For example, 12 V across 4 Ω gives 3 A.
What is electrical power?
Power is the rate of energy transfer: P = V × I, measured in watts (W). It can also be expressed as P = I²R or P = V²/R.
What units does Ohm's law use?
Voltage in volts (V), current in amperes (A), resistance in ohms (Ω), and power in watts (W).