Electricity Cost Calculator
Calculate your electricity usage costs, estimate your monthly bill, and compare energy consumption across different appliances.
How the electricity cost calculator works
This calculator estimates your daily, monthly, and yearly electricity costs based on your appliance’s power rating (in watts), how many hours you use it per day, and your local electricity rate per kilowatt-hour (kWh). Simply enter your appliance details, and the calculator will show you exactly how much it costs to run.
For example, a 100W light bulb used for 5 hours a day at 25p per kWh costs about 12.5p per day, or £3.75 per month. Use this tool to identify energy-hungry appliances and make smarter choices about your electricity usage.
Step 1: Appliance Details
Understanding Power Ratings
Watts measure how much electricity an appliance uses. To convert watts to kilowatts, divide by 1,000. A 150W appliance uses 0.15 kW per hour. The higher the wattage, the more it costs to run.
Step 2: Usage & Rate
Energy Saving Tips
Reduce your electricity bill by using energy-efficient appliances, switching to LED lighting, unplugging devices on standby, and using appliances during off-peak hours if available.
Electricity Cost Results
Estimated Monthly Electricity Cost
Cost Comparison by Usage
| Usage (hrs/day) | Daily Cost | Monthly Cost | Yearly Cost | Energy (kWh/mo) |
|---|
Cost Breakdown by Time Period
Electricity Cost Formula
Cost = Power (kW) × Hours × Rate (per kWh)
First convert watts to kilowatts by dividing by 1,000. Then multiply by the number of hours used and the electricity rate. For monthly costs, multiply by the number of days used per month.
Frequently Asked Questions
How is electricity cost calculated?
Electricity cost is calculated by multiplying the power consumption in kilowatts (kW) by the number of hours used, then multiplying by the electricity rate per kWh. The formula is: Cost = Power (kW) × Hours × Rate (per kWh).
What is a kilowatt-hour (kWh)?
A kilowatt-hour (kWh) is a unit of energy equal to 1,000 watt-hours. It represents the amount of energy used by a 1,000-watt appliance running for one hour. Electricity bills are typically measured in kWh.
What is the average electricity cost per kWh in the UK?
As of 2026, the average electricity cost in the UK is around 24-28 pence per kWh, though rates vary by supplier and region. Ofgem’s price cap typically sets the maximum rate suppliers can charge.
How do I reduce my electricity bill?
To reduce your electricity bill, use energy-efficient appliances, switch to LED lighting, unplug devices on standby, use appliances during off-peak hours if on a time-of-use tariff, and consider smart meters to track usage.
What is the difference between watts and kilowatts?
A watt (W) is a unit of power. A kilowatt (kW) is 1,000 watts. To convert watts to kilowatts, divide by 1,000. For example, a 100-watt light bulb uses 0.1 kW of power.
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