Calculator
Ohm’s Law: Current and Power Calculator
Change the inputs to match your equipment. Results update automatically.
Formula
I = U / RP = U × I = U² / R Worked example
At 24 V and 120 Ω, I = 24/120 = 0.20 A and P = 24 × 0.20 = 4.80 W. Check resistor ratings and temperature derating separately.
Scope and interpretation
This assumes a constant ideal resistance. Reactive AC loads require impedance; do not use this model to calculate motor current.