learn.howToCalculate
learn.whatIsHeading
Ohm's Law relates voltage, current, and resistance in electrical circuits. This calculator solves for any one of the four quantities — voltage (V), current (I), resistance (R), or power (P) — given any two known values.
Formel
V = IR · P = IV = I²R = V²/R
Steg-för-steg-guide
- 1Enter any two known values (V, I, R, or P)
- 2The calculator solves the remaining two using Ohm's Law and the power formula
- 3Results apply to DC circuits and to AC circuits at unity power factor
Lösta exempel
Ingång
V = 12V · R = 47Ω
Resultat
I = 12/47 ≈ 0.255 A · P = 12 × 0.255 ≈ 3.06 W
A 1/4W resistor would overheat here — use at least a 1/2W rated part
Vanliga misstag att undvika
- ✕Applying Ohm's Law to non-linear components (diodes, transistors)
- ✕Forgetting unit prefixes: mA, kΩ, mW
Redo att beräkna? Prova den kostnadsfria Ohm's Law-kalkylatorn
Prova själv →