Appliance Energy Audit Calculator

This appliance energy audit calculator estimates monthly kWh use and electricity cost for multiple household devices. It is broader than a single appliance electricity cost check because it ranks several appliances in one view.

Enter each appliance's wattage, hours used per day, days used per month, and your electricity unit rate. The calculator estimates kWh and cost per appliance, then totals the monthly energy use and highlights the biggest contributors.

Use it when you want to understand where electricity spending may be coming from, compare a heater with a dryer, see whether a fridge or freezer is worth investigating, or decide which usage habit is most likely to save money.

It does not read your smart meter, identify appliances automatically, or include standing charges. It is a planning tool that turns appliance labels and usage assumptions into a ranked home energy audit.

Suppose a 1,500 watt space heater runs for 2 hours on 20 days in a month. That is 60 kWh before tariff costs are applied. At £0.28 per kWh, the heater costs about £16.80 for the month.

A tumble dryer at 2,500 watts for 45 minutes on 12 days uses about 22.5 kWh. A fridge freezer might have a lower label wattage but runs repeatedly across the month, so its total can still matter.

The value of an audit is seeing those items side by side. Small devices that feel noticeable may cost little, while heating, drying, cooling, cooking, and refrigeration often dominate the bill because their wattage or runtime is higher.

Electricity billing is based on kilowatt-hours. A 1,000 watt appliance running for one hour uses 1 kWh. A 2,000 watt heater running for one hour uses 2 kWh, while a 100 watt device running for ten hours also uses 1 kWh.

That is why both wattage and time matter. A high-wattage appliance used briefly may cost less than a lower-wattage device that runs all day. The calculator combines both pieces so the result is easier to compare.

For appliances with variable power draw, use a realistic average if you can find one. A washing machine, fridge, heat pump, or computer may not draw its peak wattage continuously, so a plug-in power meter can improve the estimate.

Start with the highest-cost rows rather than spreading attention equally across every device. Reducing a heater, dryer, air conditioner, immersion heater, or old freezer can save more than unplugging several tiny chargers.

Test behaviour changes before assuming a replacement is worth buying. Lowering daily runtime, reducing temperature settings, line-drying, using eco cycles, batch cooking, or moving a device to off-peak hours may change the result without a purchase.

If you are comparing a new appliance with an old one, enter both as separate rows. The monthly difference can be multiplied across a year and then compared with the purchase price.

For shared homes, the ranking can make conversations easier because it shifts the discussion away from blame and toward the appliances that actually change the bill.

This calculator does not include standing charges, time-of-use tariffs, demand charges, solar export, battery storage, or seasonal changes in heating and cooling. Use the unit rate from your bill and rerun the audit when usage changes.

Wattage labels can show maximum draw rather than average consumption. Manufacturer energy labels, smart plugs, and real meter readings may give better data for expensive or always-on devices.

For vehicle charging, use the EV charging cost calculator. For a single device quick check, the electricity cost calculator is still the simpler page.