How Much Electricity Does Your Home Use?

Where the electricity actually goes

The four items checked by default above (a refrigerator, whole-home LED lighting, a Wi-Fi router, and a TV with a streaming box) are meant to approximate the baseline nearly every occupied home carries regardless of who lives there or what season it is. Added together they come to 1.2 + 0.9 + 0.24 + 0.6 = 2.94 kWh a day, or about 2.94 × 30 ≈ 88.2 kWh a month, before a single major appliance is switched on. That baseline is worth noticing on its own, because it's roughly the floor a bill never drops below even in an empty house; everything checked on top of it is where the real variation between households, and between seasons, actually comes from.

Every appliance on the reference table below falls into one of three rough tiers, and the tier matters more than any single number for understanding where a bill comes from.

The first tier is the baseline described above: things that draw power continuously or for hours every single day regardless of season, such as a refrigerator, a chest freezer, or a router that stays plugged in and idling. None of these individually pulls much wattage; a refrigerator at 150 W running 8 hours a day works out to 150 ÷ 1000 × 8 = 1.2 kWh, and a router left on around the clock at 10 W adds 10 ÷ 1000 × 24 = 0.24 kWh. Added together, this tier forms a floor a house rarely drops below, even during a week away from home with almost nothing else running.

The second tier is where most of a typical bill actually comes from: heating, cooling, and water heating. These loads draw far more power per hour than anything in the baseline tier, and even a few hours of runtime a day adds up fast. Central air conditioning at 3,500 W running 4 hours a day works out to 3,500 ÷ 1000 × 4 = 14 kWh in a single day, more than ten refrigerators' worth of electricity, and an electric water heater at 4,000 W for 2 hours a day adds another 8 kWh. Neither of these runs at a flat, predictable rate in a real home, since a compressor cycles and a thermostat cuts a heater off once a tank reaches temperature, so the table's figures are a typical daily average rather than a constant draw.

The third tier is occasional, high-wattage tasks (a range, a clothes dryer, a dishwasher) that pull a lot of power but only for a fraction of an hour or two a day. A clothes dryer at 3,000 W for about 42 minutes (0.7 hours) a day comes out to 3,000 ÷ 1000 × 0.7 = 2.1 kWh, similar in scale to a full day of lighting, but concentrated into one short, heavy burst instead of spread evenly across the day.

None of this adds up to one universal household number, because the mix of tiers varies enormously by climate, house size, and who's living there. A home running central air conditioning through a hot summer carries a very different second-tier load than the same home in a mild spring month with the compressor off entirely, and a house with a pool pump or a well pump running on the third tier's schedule looks different again from an apartment with neither. That's the entire reason the checklist above exists instead of a single averaged household figure: it lets the reference table's typical values apply only to what's actually present in a given home, rather than forcing every household into the same generic total.

From kWh on this page to a dollar figure on the bill

Every number on this page stops at kilowatt-hours on purpose. A utility bill multiplies that kWh figure by a rate in dollars per kWh, and that rate is where this page's job ends and the kilowatt-hour cost calculator's job begins: it takes a daily or monthly kWh total, like the one the checklist above just produced, and a local rate, to work out the resulting daily, monthly, and annual cost, including how tiered or time-of-use rates change the answer.

There's a reason the two calculations live on separate pages rather than being folded into one estimator. The rate itself has nothing to do with how many appliances a home runs; it's set by the utility, the plan, the season, and sometimes the time of day, and it changes independently of anything in the checklist above. Keeping the two steps apart also makes each one easier to audit: if a monthly total looks wrong, the kWh side (whether the right appliances are checked and the hours are realistic) and the rate side (whether the right dollar-per-kWh figure is being used) can be checked separately instead of guessing which piece of a combined number is off.

The distinction between power and energy shows up here too. Kilowatts describe a rate, kilowatt-hours describe a quantity accumulated over time, and the difference between the two units is covered on its own on the kilowatts to kilowatt-hours page. The same daily kWh figure produced above is also the starting point for sizing a home solar array on the solar system size page, and for converting any of this page's wattage figures into kilowatts on the watts to kilowatts page.