Appliance Energy Cost Calculator

Estimate what an appliance costs to run from watts, amps, an EnergyGuide label, or measured kWh. Use it for heaters, dehumidifiers, fridges, TVs, computers, dryers, and other household loads.

Reviewed and updated June 29, 2026

Use it when you want to know

What a device adds to your billEstimate daily, monthly, and yearly cost from the numbers you already have.
Whether the label or meter is betterUse watts, amps, annual kWh, or a plug-in monitor reading.
How much rate changes matterCompare your current rate against lower and higher electricity prices.

Calculator

Estimate appliance running cost

Start with the number you have. You can use watts from the label, amps and volts, annual kWh from an EnergyGuide label, or measured kWh from a plug-in monitor.

What number do you have?

WattsAmps & voltsAnnual kWhMeasured kWh

Appliance presetPresets only prefill editable estimates. Check your appliance label when possible.

Running watts

Use the wattage printed on the appliance or power adapter.

Hours used per dayDays in month

Duty cycle

Use 100% for simple devices. Lower this for appliances that cycle on and off.

Electricity rate

¢/kWh

Starting estimate. Replace it with your total per-kWh bill rate.Standby watts

Optional. Added only in watts and amps modes.Currency

Bill rate helper: for usage estimates, add supply or generation charges plus delivery or distribution charges. Fixed customer fees are not part of the per-kWh running cost.

Guide

How to estimate appliance electricity cost

The calculator is fastest when you already know the number to enter. Use this guide to choose the right input, read your electric bill rate, and understand why some appliances are harder to estimate from the label alone.

Start with the best number you can find

For a simple device such as a lamp, TV, computer, or space heater, running watts are usually enough. Enter the wattage, how many hours you use it per day, and your total electricity rate.

For appliances with an EnergyGuide label, annual kWh is often a better starting point than nameplate watts. Refrigerators, freezers, dishwashers, and washers are tested as whole appliances, so the annual kWh estimate already accounts for typical cycling and usage patterns.

For plug-in appliances that cycle on and off, a meter reading is best. A plug-in electricity monitor can record actual kWh over a normal day or week, which is more useful than guessing how often the compressor, heater, or motor is running.

Basic formulakWh = watts × hours ÷ 1,000

Then multiply kWh by your electricity rate. Example: 500 watts for 4 hours is 2 kWh. At 18.8 cents per kWh, that costs about $0.38 per day.

Use your total per-kWh rate

Many utility bills split electricity into supply, generation, delivery, and distribution charges. For a practical appliance running-cost estimate, add the per-kWh usage charges together. Fixed monthly customer fees are separate and should not be assigned to one appliance.

Treat cycling appliances as estimates

Dehumidifiers, refrigerators, window ACs, heat pumps, and some dishwashers do not use full power all day. Their cost depends on settings, room conditions, season, humidity, ventilation, door openings, and how hard the appliance has to work.

Look first at big heat and cooling loads

When a bill seems high, start with space heaters, electric dryers, AC units, dehumidifiers, pool pumps, well pumps, old refrigerators, and always-on computers or servers. Small chargers and LED lights usually matter less unless there are many of them running all the time.

FAQ

Appliance electricity cost questions

How much does a 500 watt appliance cost to run?

At 18.8 cents per kWh, a 500 watt appliance running 4 hours per day uses 2 kWh per day and costs about $0.38 per day, $11.28 for a 30-day month, or $137.24 per year.

Do I use supply rate, delivery rate, or both?

For a practical running-cost estimate, use the total per-kWh rate you pay for extra usage. On many bills that means adding supply or generation charges plus delivery or distribution charges. Fixed monthly fees are separate.

What is the difference between watts and kWh?

Watts measure how fast an appliance uses power at a moment in time. Kilowatt-hours measure total energy used over time. A 1,000 watt appliance running for 1 hour uses 1 kWh.

Why is my refrigerator or dehumidifier estimate only approximate?

Refrigerators, dehumidifiers, air conditioners, and similar appliances cycle on and off. Nameplate watts show draw while running, not necessarily the average over the whole day.

Is a plug-in energy monitor more accurate?

Yes, for plug-in appliances. A monitor can record real kWh over hours or days, which is usually better for cycling devices than guessing from the label alone.

Does this include taxes and fixed utility fees?

No. This calculator estimates usage-based electricity cost. Utility bills may also include taxes, fixed customer charges, minimum bills, demand charges, or time-of-use rates.