1. What is the Energy Usage Calculator?

The Energy Usage Calculator estimates electricity consumption in kilowatt-hours (kWh) based on appliance power rating and usage time. This calculation follows the approach recommended by Martin Lewis for understanding energy costs.

2. How Does the Calculator Work?

The calculator uses the energy formula:

Where:

• \( kWh \) — Kilowatt-hours (energy consumption)
• \( P \) — Power in watts (W)
• \( hours \) — Time in hours

Explanation: The formula converts watts to kilowatts (dividing by 1000) and multiplies by usage time to calculate total energy consumption.

3. Importance of Energy Calculation

Details: Understanding energy usage helps estimate electricity costs, identify energy-intensive appliances, and make informed decisions about energy conservation.

4. Using the Calculator

Tips: Enter the power rating of your appliance in watts and the number of hours it's used. Check appliance labels for power ratings or use typical values for common devices.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: The calculation provides a good estimate, but actual consumption may vary based on appliance efficiency, usage patterns, and power fluctuations.

Q2: How do I find the power rating of my appliance?
A: Check the manufacturer's label, manual, or specification sheet. Most appliances display their power consumption in watts (W) or kilowatts (kW).

Q3: Can I calculate cost from this result?
A: Yes, multiply the kWh result by your electricity rate (price per kWh) to estimate the cost of running the appliance.

Q4: What's a typical power rating for common appliances?
A: LED bulb: 5-15W, Laptop: 50-100W, Refrigerator: 100-250W, Microwave: 600-1200W, Electric kettle: 1500-3000W.

Q5: Why divide by 1000 in the formula?
A: We divide by 1000 to convert watts to kilowatts, as energy is typically billed in kilowatt-hours rather than watt-hours.