Electricity Cost Calculator — Appliance Energy Consumption
An electricity consumption calculator converts an appliance's power rating into what it actually costs you per month. The chain is simple: power in watts × hours of use = energy in watt-hours; divide by 1,000 to get kilowatt-hours (kWh), the unit your utility bills; multiply by your tariff to get the cost. Add several devices — refrigerator, air conditioner, shower, TV, computer — and the calculator totals your estimated monthly bill and shows which appliances dominate it.
The power rating is printed on the appliance label or in its manual, but real consumption depends on usage patterns: a 900 W microwave used 15 minutes a day consumes far less than a 150 W refrigerator compressor cycling all day. Devices with thermostats or inverters (fridges, air conditioners) draw their rated power only part of the time, so treat results as estimates. Reviewing the list usually reveals that a handful of heat-producing appliances — electric showers, heaters, dryers, AC — account for most of the bill.
How it works
Energy (kWh) = Power (W) × hours per day × days ÷ 1,000. Monthly cost = kWh × price per kWh. Example: a 1,400 W air conditioner running 8 h/day for 30 days uses 1,400 × 8 × 30 ÷ 1,000 = 336 kWh.
Use cases
- Estimating the monthly cost of an air conditioner before the summer season
- Finding out which appliances are responsible for a high electricity bill
- Comparing the running cost of two appliances with different power ratings
- Calculating how much a gaming PC, server, or mining rig adds to the bill
- Checking the savings from replacing old bulbs or appliances with efficient ones
- Projecting the impact of a tariff increase on your household budget
Frequently asked questions
How do I calculate the electricity consumption of an appliance?
Multiply the appliance's power in watts by the hours it runs, then divide by 1,000 to convert to kilowatt-hours: kWh = W × h ÷ 1,000. For a month, multiply by the number of days of use. A 100 W device running 5 hours a day for 30 days consumes 100 × 5 × 30 ÷ 1,000 = 15 kWh.
How do I convert kWh to money on my electricity bill?
Multiply the kWh by the price per kWh shown on your bill, which includes energy, distribution, and taxes in most countries. If your bill only shows the total, divide the amount paid by the kWh consumed to get your effective rate. Some utilities use time-of-use or tiered tariffs, in which case apply the rate that matches when or how much you consume.
Which household appliances consume the most electricity?
Appliances that produce heat or cold dominate: electric showers and water heaters (3,500–7,500 W), air conditioners (800–2,500 W), electric ovens, clothes dryers, and space heaters. Refrigerators draw modest power (100–250 W) but run all day, so they still rank high in monthly kWh. Electronics like TVs, routers, and phone chargers are usually minor by comparison.
Where do I find the wattage of my appliance?
Check the rating label on the back or bottom of the device, the specifications page of the manual, or the manufacturer's website. The value appears in watts (W) or kilowatts (kW); if only voltage (V) and current (A) are listed, multiply them: W = V × A. For variable devices such as inverter air conditioners, the label shows a range — use an average or a plug-in energy meter for accuracy.
Do appliances on standby consume electricity?
Yes. TVs, set-top boxes, game consoles, microwaves, and chargers keep drawing typically 0.5–10 W each while on standby. Individually that is little, but a home with many devices can accumulate a noticeable share of the bill over a year. Power strips with switches or smart plugs make it easy to cut standby loads completely.