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Electricity Cost Calculator

Find out what any appliance really costs to run — per hour, day, month and year — from its wattage and your electricity rate.

Quick answer

Cost = watts ÷ 1,000 × hours used × price per kWh. A 1,000 W appliance running 1 hour at $0.17/kWh costs 17¢. Pick an appliance for typical wattages: air conditioner, space heater, refrigerator.

  • Free
  • No sign-up
  • Energy
  • Updated October 2026
W

On the label or manual. 1 kW = 1000 W.

%

Share of time it actually draws full power. AC and fridges cycle on and off; lights and TVs are 100%.

Find it on your bill (cents ÷ 100).

Cost per month (30 days)

$40.80

Cost per day
$1.36
Cost per year
$496.40
Cost per hour of use
$0.17
Energy per day
8 kWh
Energy per month
240 kWh
Show the working
  1. 1,000 W × 8 h × 100% × 1 ÷ 1000 = 8 kWh/day
  2. 8 kWh × $0.17 = $1.36 per day

About the Electricity Cost calculator

Your bill charges for energy in kilowatt-hours (kWh). One kWh is 1,000 watts used for one hour, so a 2,000 W heater running for 30 minutes uses 1 kWh. Multiply by your price per kWh and you have the cost.

The wattage on a label is the maximum draw. Appliances with a compressor or thermostat — fridges, air conditioners, heaters — switch on and off, so they average well below that. Use the “average load” field to reflect this; the appliance pages below have realistic starting values.

Your price per kWh is on your bill. If your tariff has peak and off-peak rates, run the calculation once for each period.

How to use it

  1. Find the wattage on the appliance label or manual (look for W or kW; 1 kW = 1,000 W).
  2. Enter how many hours a day it’s on.
  3. Set the average load — 100% for lights and TVs, lower for cycling appliances.
  4. Enter your electricity price per kWh from your bill.
  5. Read the cost per day, month and year.

The formula

Cost = Watts × Hours × Load ÷ 1000 × Price per kWh

  • Watts × Hours ÷ 1000 gives kWh.
  • Multiply kWh by your tariff to get cost.

Worked example

A 1,500 W space heater, 5 hours a day

  1. 1,500 × 5 ÷ 1,000 = 7.5 kWh per day.
  2. At $0.17 per kWh: 7.5 × 0.17 = $1.28 per day.
  3. Over 30 days: about $38.25.

Frequently asked questions

How do I find my price per kWh?

Divide the energy charge on your bill by the kWh used, or look for the unit rate on the tariff section. Include taxes and per-kWh delivery charges for a realistic figure.

What uses the most electricity at home?

Heating and cooling are usually the largest loads, followed by water heating, tumble dryers, electric ovens and refrigerators. Small electronics are individually cheap but add up when left on standby.

Does an appliance on standby use electricity?

Yes, typically 0.5–5 W. Enter the standby wattage with 24 hours a day to see its yearly cost.

Results are estimates for planning — check critical figures with a professional or the official source.

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