1. What is Kilowatt-hour (kWh)?

A kilowatt-hour (kWh) is a unit of energy that represents the amount of electrical energy consumed when a 1,000-watt appliance runs for one hour. It's the standard unit used by electric utilities for billing purposes.

2. How Does the Calculator Work?

The calculator uses the energy formula:

Where:

• \( V \) — Voltage (volts)
• \( I \) — Current (amperes)
• \( h \) — Time (hours)
• 1000 — Conversion factor from watts to kilowatts

Explanation: The formula calculates the total energy consumption by multiplying voltage, current, and time, then converting from watt-hours to kilowatt-hours.

3. Importance of Energy Calculation

Details: Calculating kWh helps estimate electricity costs, compare appliance efficiency, and understand energy consumption patterns for better energy management.

4. Using the Calculator

Tips: Enter voltage in volts, current in amps, and time in hours. All values must be positive numbers. For DC circuits, use actual voltage. For AC circuits, use RMS voltage.

5. Frequently Asked Questions (FAQ)

Q1: How do I convert kWh to cost?
A: Multiply kWh by your electricity rate (per kWh). For example, 5 kWh at $0.12/kWh = $0.60.

Q2: What's the difference between kW and kWh?
A: kW is power (rate of energy use), kWh is energy (power × time). A 1 kW device running for 1 hour uses 1 kWh.

Q3: Can I use this for three-phase systems?
A: For balanced three-phase, multiply by √3 (about 1.732). Formula becomes: kWh = (V × I × h × √3)/1000.

Q4: How accurate is this calculation?
A: It's accurate for constant loads. For variable loads, you'd need to calculate energy use at different time intervals.

Q5: What if I know watts instead of volts and amps?
A: kWh = (watts × hours)/1000. Watts = volts × amps, so both methods are equivalent.