Making Sense of the Figures

Kilowatts measure power: the rate of energy use. Kilowatt-hours measure energy used over time. A steady 1 kW load running for two hours uses 2 kWh.

For a household calculation, start with the units guide.

Unit rates, fixed charges, billing length, taxes or adjustments may have changed. Compare matching dates and charge categories, not only the total.

The monthly review guide separates these layers.

Not necessarily. A monitor provides information, not automatic reductions. Its value depends on actionable findings, purchase and installation costs, subscriptions and your tariff.

No. Similar LED light output may need similar power while lit, and a connected bulb can use standby energy. Controls help only when they usefully change operation.

See the lighting comparison for an example with standby included.

Only as a stated approximation. Devices that cycle or change power need representative measurements or suitable consumption data rather than maximum watts multiplied by every hour.

Use a suitable meter over a period long enough to capture normal operating states. Follow the meter instructions and check its low-load accuracy. There is no single duration suitable for every device.

Internal panel work can expose dangerous live parts. Use a qualified electrician and follow local rules and manufacturer instructions; do not open the enclosure as a casual household experiment.

No. The supplied worksheets calculate locally in your browser. They do not connect to a meter, request account access or save your entries in site storage.

The privacy notice explains the distinction between local tools, website delivery and email.

Record a baseline, change one thing and compare similar periods. Note weather, occupancy and other changes. A small difference may remain uncertain rather than proving a cause.

Follow the small-test method and keep health, comfort and safety ahead of a target number.