What an appliance costs to run based on wattage and usage.

Electrical appliances vary hugely in running cost. A 2,000W kettle used 15 minutes daily costs about 0.12/day (44/year at 24p/kWh). A 300W TV on 5 hours costs about 0.36/day (131/year). Understanding individual appliance running cost helps prioritise which matter most for energy savings.

The math: (wattage × usage hours × rate) ÷ 1,000 = daily cost. Annualised for typical usage pattern. Electric kettles, ovens, and heaters have highest per-use cost (high wattage, short duration). Fridges and always-on devices have sustained low drain but add up across 24/7 operation.

The tool identifies which appliances are worth optimising. Replacing a 100W constantly-on device with 20W saves 80W × 24 × 365 ÷ 1,000 × 0.24 = 168/year. Replacing a rarely-used 2,000W kettle with a cheaper model saves very little because usage is short. Focus on the biggest drains.

What the result means

Annual running cost is the total electricity spend for this appliance. Per-hour cost normalises across different appliances. Use this to identify which devices are worth replacing or using less.

Quick example

With wattage of 300 and hours per day used of 5 (plus electricity rate per kwh of 0.24 and days per year used of 365), the result is 131.40. Change any figure and watch the output shift — it's often more useful to see the pattern than to memorise the formula.

Which inputs matter most

You enter Wattage (W), Hours Per Day Used, Electricity Rate per kWh, and Days Per Year Used. Frequency and unit price pull the total in different directions. The biggest surprise for most people is how small recurring amounts compound into large annual figures — that's where this calculation earns its keep.

What's happening under the hood

Wattage × hours × days ÷ 1,000 gives kWh consumed annually. Multiplied by rate per kWh for cost. The formula is listed in full below. If the number looks off, you can retrace the calculation by hand — that's the point of showing the working.

Why run the calculation

Utility bills creep. Small annual increases stack into meaningful differences over a decade. Running this once a year and switching providers when the gap widens is one of the easiest ways to keep household costs in check.

What this doesn't capture

Usage varies month-to-month; tariffs change; discounts come and go. The figure here is a clean baseline — your actual annual bill will fluctuate around it. Use the calculation to benchmark providers, not as a prediction of a specific bill.