AC Wattage Calculator
Calculate Real Power ($P$) using Voltage ($V$), Current ($I$), and Power Factor ($\cos(\varphi)$).
Inputs
Calculation and Result
Real Power ($P$):
— W
What is AC Wattage (Real Power)?
AC Wattage, formally known as Real Power ($P$ or $kW$), is the actual power consumed by an electrical circuit that performs useful work (like generating heat, motion, or light). In alternating current (AC) systems, unlike direct current (DC) systems, voltage and current can be out of phase.
The difference between the apparent power ($V \times I$) and the real power is due to reactive components (like inductors and capacitors), which store and release energy, creating Reactive Power ($Q$). The Real Power is calculated by multiplying the Apparent Power by the Power Factor, which accounts for the phase difference.
Significance and Applications: Real Power is what utilities charge consumers for. Understanding and maximizing the Power Factor (aiming for $\cos(\varphi)$ close to 1) is crucial for efficiency. Appliances with high Power Factors (e.g., LED lights, resistive heaters) are more efficient than those with low Power Factors (e.g., older motors, some fluorescent ballasts).
How to Use This Tool
- Enter RMS Voltage ($V$): Input the effective voltage of the AC source, usually 120V (North America) or 230V (Europe/Asia).
- Enter RMS Current ($I$): Input the effective current drawn by the load in Amperes.
- Enter Power Factor ($\cos(\varphi)$): This is a number between 0 and 1, representing the fraction of the apparent power that is real power. Use $1.0$ for purely resistive loads (like incandescent bulbs).
- Click ‘Calculate’: Press the button to see the substituted formula and the final Real Power ($P$) result in Watts (W).
