Appliance Energy Cost Calculator

Find out how much a specific appliance costs you per month and per year. Enter the wattage, hours of use, and your electricity rate to get an honest estimate.

What this calculator does

This tool answers a surprisingly hard question: what does this appliance actually cost me? Most people look at their electricity bill and see a single number. What they don't see is that a 20-year-old fridge might be costing $150 a year, while the dryer costs $80 and the space heater costs $220. The costs are hidden in a lump sum, and that hides the biggest opportunities for savings.

Our calculator breaks that lump sum down to a single appliance. Once you know what each device costs, you can decide where to spend your attention — and where you're wasting money without realizing it. In our experience testing typical homes, the three biggest offenders are almost always the same: the refrigerator, the water heater, and whatever heating or cooling equipment runs the longest.

How we calculate this

The math is straightforward but easy to get wrong by hand. We use the standard electricity formula that appears in every utility bill:

Let's walk through an example. Suppose you have a 1,500W space heater running 4 hours a day, and your electricity rate is $0.14 per kWh.

1. Convert watts to kilowatts: 1,500 ÷ 1000 = 1.5 kW
2. Multiply by daily hours: 1.5 kW × 4 h = 6 kWh per day
3. Multiply by 30 days: 6 × 30 = 180 kWh per month
4. Multiply by rate: 180 × $0.14 = $25.20 per month
5. Annual: $25.20 × 12 = $302.40 per year

That's a real number. For a household with two space heaters running through the winter, that's more than $600 a year — often more than the cost of simply heating the whole house with central heating if the household is already occupied.

How to find the wattage

The wattage label is usually on a sticker or plate on the back, bottom, or inside the door of the appliance. It may show a single "W" number, or it may show amps × volts. If it shows amps and volts, multiply them: a device rated at 120V and 12.5A uses 1,500W.

If you can't find the label, here are typical wattages for common appliances:

• LED bulb: 9W
• Ceiling fan: 15–75W
• Laptop: 30–70W
• Desktop PC + monitor: 100–250W
• Refrigerator: 100–200W (running average)
• Space heater: 750–1,500W
• Window AC unit: 500–1,500W
• Microwave: 600–1,500W
• Dishwasher: 1,200–1,800W
• Electric clothes dryer: 3,000–5,000W

Three important caveats

1. Fridges and ACs don't run continuously. A fridge rated at 200W doesn't use 200W all day — the compressor cycles on and off. For these appliances, use the "running average" wattage shown above, or better yet, use a plug-in energy monitor for a week to see actual usage.

2. "On" wattage isn't the whole story. Many devices draw power in standby even when they seem off. TVs, game consoles, and cable boxes are the biggest offenders. If you want to capture this, add the standby watts separately or use a smart power strip to eliminate them.

3. Your electricity rate may not be flat. If your utility has time-of-use rates, the same appliance costs more during peak hours (usually 4–9 PM). Running the dryer after 9 PM can cut that specific cost significantly.

What to do with the result

If an appliance is costing you $100+ per year, it's worth investigating. Here are common next steps:

• If it's the fridge: check the door seals, clean the coils, and set the temperature to 37°F. Full guide: How to Reduce Fridge Energy Use.
• If it's a space heater: make sure you're lowering the central thermostat when it runs. See How to Use a Space Heater Efficiently.
• If it's a TV or game console: put it on a smart power strip. See How to Use a Smart Power Strip.
• If it's a dryer: try air-drying half your loads. See How to Air-Dry Laundry Indoors.

Sources and methodology

The wattage figures above are based on the U.S. Department of Energy's appliance energy data (Energy.gov), manufacturer specifications from major appliance brands, and the U.S. Energy Information Administration's (EIA) 2024 average residential electricity rate of about $0.17/kWh. Our calculator uses the standard kWh formula shown in every utility bill, and we've tested the results against real bill data from typical U.S. households.

We don't store the numbers you enter. Everything runs in your browser.

Frequently Asked Questions