Appliance Running Cost Calculator

Enter Calculation

Appliance Power (watts)

Hours Used Per Day

Days Per Month

Electricity Rate (cost per kWh)

Results

Estimated Monthly Running Cost

2.55

per month

Daily cost	0.085
Yearly cost	31.03
Energy used per day	0.5 kWh
Energy used per month	15 kWh

What This Calculator Does

The Appliance Running Cost Calculator tells you how much it costs to run any electrical device. Smart plugs and energy monitors report an appliance's power draw in watts and how many hours it runs — plug those numbers in here, add your electricity rate, and you instantly see the daily, monthly and yearly cost. It works with any currency: just enter your cost per kWh in your own currency and the results come back in the same units.

How to Use It

Enter the appliance power in watts (a smart plug shows this live, or check the device's label or manual). Enter how many hours per day it runs and how many days per month you use it. Finally enter your electricity rate — the price you pay per kilowatt-hour (kWh), found on your utility bill. The calculator returns the cost per day, per month and per year, plus the energy consumed in kWh.

The Formula Explained

Electricity is billed per kilowatt-hour. One kWh is 1000 watts running for one hour. So the cost formula is:

$$\text{Cost} = \frac{\text{watts}}{1000} \times \text{hours} \times \text{cost per kWh}$$

Dividing watts by 1000 converts power to kilowatts. Multiplying by hours gives kilowatt-hours (the energy used). Multiplying by your rate gives the money cost.

The running cost formula: watts converted to kilowatts, multiplied by hours of use and your rate per kWh.

Worked Example

Suppose a space heater draws 1500 watts, runs 4 hours a day, 30 days a month, and your rate is $0.17 per kWh. Energy per day = \(\frac{1500}{1000} \times 4 = 6\) kWh. Daily cost = \(6 \times 0.17 = \$1.02\). Monthly cost = \(\$1.02 \times 30 = \$30.60\). Yearly cost = \(\$1.02 \times 365 = \$372.30\).

Worked example: the same daily cost scaled up to monthly and yearly totals.

FAQ

Where do I find the watts? A smart plug or plug-in energy monitor displays real-time wattage. Otherwise check the appliance rating label or manual.

What is a kWh? A kilowatt-hour is the standard unit of electricity billing: 1000 watts used for one hour. Your bill lists your rate per kWh.

Why use 365 days for the yearly figure? The yearly cost projects your daily cost across a full year, which assumes consistent daily usage. The monthly cost uses the days-per-month value you enter.