Electricity Cost Calculator

Calculate electricity costs for appliances. Enter the power consumption (watts), hours used per day, and electricity rate to automatically calculate daily, monthly, and yearly costs.

Calculator

Result

Daily Usage
0.00 kWh
Daily
$0.00
Monthly
$0.00
Yearly
$0.00

Formula & Guide

Formula

k

kWh Calculation

kWh = (Watts × Hours) ÷ 1000

Convert watts to kilowatt-hours

$

Cost Calculation

Cost = kWh × Rate ($/kWh)

Multiply kWh by electricity rate

Formula Variables

W

Watts

Power consumption of the appliance in watts

H

Hours

Number of hours the appliance is used per day

kWh

Kilowatt-hours

Energy consumption (Watts × Hours ÷ 1000)

R

Rate

Electricity rate in dollars per kWh ($/kWh)

C

Cost

Total cost (kWh × Rate)

Step-by-Step Scenario

Example Scenario

Power

100W

Hours

8 hours/day

Rate

$0.12/kWh

1

Calculate Daily kWh

  • kWh = (100 × 8) ÷ 1000 = 0.8 kWh/day

Convert watts and hours to kilowatt-hours

2

Calculate Cost

  • Daily = 0.8 × $0.12 = $0.096
  • Monthly = $0.096 × 30 = $2.88
Yearly = $35.04

Additional Examples

LED Light

Power: 10W

Hours: 8 hours/day

Monthly Cost

$0.29

Refrigerator

Power: 150W

Hours: 24 hours/day

Monthly Cost

$12.96

Characteristics of Electricity Cost

kWh Calculation

Converts watts and hours to kilowatt-hours (kWh), the standard unit for electricity billing.

Multiple Time Periods

Shows daily, monthly, and yearly costs. Helps understand long-term electricity expenses.

Rate Customization

Enter your local electricity rate ($/kWh). Average US rate is $0.12-0.15/kWh. Check your bill for exact rate.

Energy Efficiency

Helps identify energy-efficient appliances. Lower wattage and fewer hours = lower cost. Useful for cost comparison.

Important Notes

  • Electricity cost = (Watts × Hours ÷ 1000) × Rate ($/kWh). 1000 watts for 1 hour = 1 kWh.
  • 1 kWh = 1000 watts used for 1 hour. This is the standard unit for electricity billing. Check your bill for your rate.
  • Find your electricity rate on your bill. Average US rate is $0.12-0.15/kWh. Rates vary by location and provider.
  • High-consumption appliances: HVAC, water heaters, refrigerators, dryers. Low-consumption: LED lights, electronics, chargers.
  • To reduce costs: Use energy-efficient appliances (LED, Energy Star), unplug unused devices, use power strips, adjust thermostat.

Frequently Asked Questions

Find answers to common questions about electricity cost calculation.