Electricity Cost Calculator — Appliance Running Costs

Every appliance in your home converts watts and hours into money, but the label never says how much. This calculator does the conversion: pick a device from the list (or enter the wattage yourself), say how many hours a day it runs and what you pay per kilowatt-hour, and it shows the energy used and the cost per day, per month and per year.

The math behind it is one line: kWh = watts × hours ÷ 1000. A 1500 W appliance running 8 hours a day uses 12 kWh daily — 360 kWh over a 30-day month — and the cost is just that energy multiplied by your tariff. What the calculator adds is the three time scales side by side: a load that looks like pocket change per day often turns out to be a serious line item per year, which is exactly how always-on devices like refrigerators and routers hide their cost.

The built-in appliance profiles are honest typical values, not measurements of your hardware: a refrigerator is listed at its 24-hour average (the compressor cycles, so the average is far below the peak), while a space heater or kettle genuinely draws its full rating whenever it is on. Use the profiles for a first estimate, then check the label or nameplate on your own device — every field stays editable.

The calculator is currency-agnostic: enter the price per kWh from your bill in whatever currency you pay, and results come back in the same units. Like every tool on this site it runs entirely in your browser — no tariffs, appliance lists or usage patterns are uploaded or stored anywhere.