MiniCalci

Calculators & Converters
Everyday Math

Electricity Cost Calculator

Free electricity cost calculator to estimate monthly and annual power costs for household appliances (space heaters, AC, refrigerators, EV chargers, PCs).

Check your electricity utility bill for exact $/kWh or p/kWh supply rate

How Does This Electricity Cost Calculator Work?

High energy bills often come from unexpected "power hogs" around the house. This electricity cost calculator allows you to enter any appliance's wattage and daily runtime (or pick from standard presets) to see exactly how much it costs per hour, per day, per month, and over a full year in USD, GBP, AUD, CAD, or EUR.

The Electricity Cost Calculation Formula

  • Kilowatts (kW) = Appliance Watts / 1,000
  • Daily kWh = Kilowatts × Hours Run per Day
  • Monthly kWh = Daily kWh × 30
  • Monthly Electricity Cost = Monthly kWh × Cost per kWh
  • Annual Electricity Cost = Daily kWh × 365 × Cost per kWh

Worked Example: Running a 3,500W Central AC Unit

  1. Power in kW: 3,500 W / 1,000 = 3.5 kW.
  2. Daily Consumption (8 hours run): 3.5 kW × 8 hrs = 28 kWh per day.
  3. Monthly Consumption: 28 kWh × 30 days = 840 kWh/month.
  4. Monthly Cost (at $0.16/kWh): 840 kWh × $0.16 = $134.40 per month.

Estimated Wattages of Common Home Appliances

Appliance Typical Power (Watts) Daily Usage Est. Monthly Cost ($0.16/kWh)
Space Heater 1,500 W 6 hrs $43.20
Central Air Conditioning 3,500 W 8 hrs $134.40
Refrigerator (Energy Star) 150 W (duty cycle) 24 hrs $17.28
Electric Clothes Dryer 3,000 W 1 hr $14.40
Desktop Gaming PC 450 W 4 hrs $8.64
Level 2 EV Home Charger 7,200 W 4 hrs $138.24

Explore Related Money & Utility Calculators

Managing your household budget? Pair this with our Gas Mileage & Trip Cost Calculator, Salary to Hourly Wage Calculator, and Time and a Half Calculator.

Frequently Asked Questions

How do I calculate how much electricity an appliance uses?
Multiply the wattage of the appliance by the number of hours it runs per day, then divide by 1,000 to find the daily Kilowatt-hours (kWh). Multiply that number by your electricity rate per kWh. Formula: **Cost = (Watts × Hours × Rate per kWh) / 1,000**.
How much does it cost to run a 1,500W space heater?
A 1,500-watt space heater uses 1.5 kWh of electricity per hour. At the US national average rate of $0.16/kWh, it costs approximately **$0.24 per hour**, **$1.44 per 6-hour day**, or **$43.20 per month**.
What uses the most electricity in an average home?
Heating and cooling (HVAC / central air) accounts for nearly 45–50% of the average home's electric bill. The next largest consumers are electric water heaters (18%), clothes dryers (5%), refrigerators (4%), and lighting.
Where do I find my electricity rate per kWh?
Check your monthly electric utility bill under the 'Supply' or 'Generation' charges. In the US, average rates range from $0.12 to $0.28 per kWh (national avg ~$0.16). In the UK, average rates hover around 27p–30p/kWh. In Australia, rates are typically 30c–38c AUD/kWh.

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How this is calculated: This tool uses standard, well-established formulas for everyday math calculations. Results are estimates for informational and planning purposes — always double-check figures for anything with real-world consequences (e.g. ordering materials or submitting grades).