What is power in electrical circuits?

Power (P) is the rate of energy transfer, measured in watts (W). It represents how much electrical energy is used per unit time. P = V × I (voltage times current).

How is monthly electricity cost calculated?

Cost = Power (kW) × Time (hours) × Rate ($/kWh). This calculator uses the US average rate of $0.15/kWh. Your actual rate may vary by location and utility company.

What's the difference between watts and watt-hours?

Watts measure instantaneous power (rate of energy use). Watt-hours (Wh) measure total energy consumed over time. 1 kilowatt-hour (kWh) = 1000 W × 1 hour.

Can I calculate power from resistance and voltage?

Yes. P = V² / R (voltage squared divided by resistance) gives power when you know voltage and resistance.

How do I reduce my electricity bill?

Use more efficient appliances (LED bulbs, ENERGY STAR devices), reduce idle consumption, use power strips, and monitor high-power devices like air conditioners and heaters.