CalcMoon Energy

What does it cost to run that appliance?

Enter watts and hours — get kWh per day, monthly dollars and yearly energy, instantly. No sign-up, no uploads, everything runs in your browser.

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Each page is pre-filled with a realistic wattage range, so you only adjust the hours you actually use.

Appliance electricity cost calculator One calculator for every appliance: watts in, dollars out. Adjust the rate to match your own bill. Any device · fully adjustable Refrigerator Fridges cycle on and off, so the honest way to estimate is by daily kWh, not running watts. Plan on 1–2 kWh a day for a modern unit; a 2005-era or extra-cold unit can hit 3. 100–400 W · ~1.5 kWh/day TV Screen size and panel type matter more than brand. Modern LED sets are efficient; OLED is roughly 1.5× the draw of the same-size LED, and old plasma sets can be 3×. 60–180 W · 4h/day Microwave Microwaves are power-hungry but time-shy. Even heavy use costs a couple of dollars a month, which makes them a poor target for energy-saving effort. 1,200–1,800 W · minutes/day Dehumidifier Dehumidifiers are the sleeper cost in a humid climate. Because they run for long stretches, they often cost more per month than a refrigerator. 300–700 W · runs for hours Window AC Match BTU to room size and the cost falls into place. Oversizing a window AC is a common and expensive mistake — it cools fast, then short-cycles. 500–1,500 W · by BTU Space heater There is no such thing as an efficient electric resistance heater — 1,500 W in is 1,500 W of heat, whatever the marketing says. Cost is set by hours, not brand. 750–1,500 W · highest hourly cost Washing machine Washing machines are cheap to run because they run briefly — but the heater dominates. Switching from a hot to a cold wash cuts energy use by roughly 75%. 400–1,400 W · ~1 cycle/day Dishwasher Dishwashers are efficient per dish — often less water and energy than hand washing — but the drying cycle and high-temperature wash are where the money goes. 1,000–1,500 W · ~1 cycle/day Water heater After heating and cooling the house itself, the water heater is usually the biggest single electricity consumer. A tank standing at 60°C loses heat around the clock. 3,500–4,500 W · biggest load Heat pump The number on the label is misleading for a heat pump, because it does not make heat — it moves it. Comparing watts against a space heater is the wrong comparison; compare cost per unit of heat delivered. 1,500–5,000 W · COP 2.5–4 Air fryer An air fryer is a small, fast convection oven. It draws similar wattage to a big oven but runs for a quarter of the time in a much smaller cavity, so it usually wins on energy. 1,400–1,800 W · short bursts Coffee maker Brewing a pot costs a penny or two. Leaving the warming plate on for two hours afterwards can cost more than the brewing itself. 600–1,200 W · plate drains power Hair dryer Hair dryers have a high hourly cost and a low monthly cost. Ten minutes a day at 1,500 W is about 7.5 kWh a month — roughly $1.25. 1,200–1,875 W · minutes Ceiling fan A ceiling fan costs pennies to run. It does not lower the air temperature — it cools people by moving air over their skin, which is why it only helps when someone is in the room. 15–75 W · per fan Portable AC Portable ACs are convenient and genuinely power-hungry. The single-hose design pulls cooled room air out the window, which is why they often cost more to run than a window unit that cools the same room. 800–1,400 W · by BTU Electric blanket Heating a person directly costs a fraction of heating a room. An electric blanket running all night costs less than a space heater running for one hour. 60–150 W · cycles Clothes dryer Drying clothes with electricity is the single most expensive routine household task after heating and hot water. A heat pump dryer uses roughly half the energy of a vented one. 2,500–5,000 W · most per load Chest freezer Chest freezers are more efficient than uprights of the same volume, because cold air is heavy and stays in the tub when you open the lid. 100–300 W · ~11 kWh/week Vacuum cleaner Vacuuming is a low-energy task because it is brief. The bigger difference is between a 1,400 W corded upright and a 300 W cordless, which moves less air but uses a fifth of the power. 300–1,400 W · short use Pool pump A single-speed pool pump running eight hours a day can cost more than every appliance in the kitchen combined. Variable-speed pumps cut that by 50–75%. 1,000–2,500 W · biggest in pool homes Electric kettle Kettles are the most efficient way to heat water in a home, because the element is immersed and almost no heat escapes. The only waste is boiling more water than you need. 1,500–3,000 W · 1–3 min EV charger Charging an EV is the largest single electrical load a home will ever draw. Cost depends almost entirely on battery size and your rate, and off-peak tariffs can halve it. 1.4–11 kW · by charger type Sump pump Sump pumps are impossible to estimate from a label, because runtime depends entirely on groundwater. Observed runtime matters far more than rated wattage. 800–1,200 W · runs on demand Electric stove Cooking accounts for a modest share of a bill, but the choice between resistive, induction and gas is one of the few appliance decisions with a clear energy winner. 1,000–3,000 W · per burner Electric furnace An electric furnace has a COP of exactly 1: every unit of electricity becomes one unit of heat. A heat pump delivers 2.5–4 units for the same electricity, which is why furnace replacement is usually the highest-return upgrade available. 10 kW–20 kW · highest heating cost Hot tub A hot tub's cost is dominated by keeping 1,500 litres of water at 38°C around the clock, not by the time you spend in it. 2,000–4,000 W · holds temp daily Deep freezer Chest-style deep freezers are among the cheapest appliances to run, because their shape keeps cold air inside and their contents act as thermal mass. 100–300 W · ~10 kWh/week

Why watts matter more than you think

A 1,500 W space heater running four hours a day uses 180 kWh a month — more than a fridge, a TV and a router combined. The appliances that quietly cost the most are almost never the ones people suspect. We built this because every search result tells you "a fridge uses about 60 W" and then stops, leaving you to do the arithmetic.

Every number here comes from the same formula your utility uses: kilowatt-hours = watts ÷ 1,000 × hours, multiplied by your rate. No estimates baked in, no affiliate upsells.