Energy Cost Calculator
Calculate electrical energy cost from power consumption, usage hours, and utility rate. Enter values for instant results with step-by-step formulas.
Reviewed by Daniel Agrici, Founder & Lead Developer
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
Daily Cost = (Watts × Hours) / 1000 × $/kWh | Monthly = Daily × 30
Kilowatt-hours (kWh) = power in watts × hours / 1000. Multiply by your electricity rate to get cost.
Worked Examples
Example 1: 100W bulb 8h/day
Problem:100W, 8h, $0.12/kWh
Solution:0.8 kWh/day × $0.12 = $0.096/day = $2.88/mo
Result:$2.88/month
Frequently Asked Questions
How do I calculate fuel cost per mile?
Divide the price per gallon by your vehicle's MPG. At $3.50/gallon with 28 MPG, your fuel cost is $0.125 per mile. For total driving costs including maintenance, insurance, and depreciation, the IRS standard mileage rate (67 cents/mile in 2024) provides a rough benchmark.
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy