Help with Energy Cost Planner.

On its rating plate, usually on the back or underneath, or on its energy label. The typical values in the app’s list are starting values only; the plate or label of your own appliance is the better source.

Fridges, freezers and ovens switch themselves off when they reach temperature, so they do not draw their rated power all the time. Either tick “It cycles on and off by itself” and give your best judgement of the share of time it is really drawing power, or enter the kWh a year from its energy label instead.

Choose “kWh a cycle” and enter the kWh for one cycle and the number of cycles a week.

Yes. Each appliance can have a standby power, and you can pick the months in which it is used at all. Outside those months it is treated as unplugged.

The unit rate in pence per kWh and the standing charge in pence per day, as they stand on your bill or in your supplier’s tariff details. If your tariff has no standing charge, enter 0. Until a tariff is complete, the app shows kilowatt-hours only.

Choose “Day and night rates”, enter both rates and the number of off-peak hours a day your tariff gives you. The app fixes no times, because they differ between suppliers, regions and meters; you can note your own. For each appliance you can then say how much of its use falls in the cheaper hours.

It uses prices as you enter them. If your prices exclude VAT, choose “Add VAT on top” and type in the rate shown on your bill. The app contains no VAT rate.

Open the tariff and type in the new ones. The app never goes online, so it cannot update prices for you.

The estimate is built from the wattages and hours you entered; your meter records what really happened. An appliance missing from the list, one used for longer than entered, or one that does not draw its rated power all the time will move the result. An estimate is not a bill and not a forecast of one.

A year is 365 days. Per day is the year divided by 365, per week is seven days, and per month is the year divided by 12. The guide in the app, under More, explains this with worked examples.

The purchase price of the new appliance divided by the saving in a year. It is an illustration that assumes your prices and habits stay the same.

Write down the numbers from left to right and ignore any shown in red. A two-rate meter has two readings; the day reading is the one that moves in the daytime.

A meter that reaches its highest number starts again from zero, and the app recognises that. So that it can, set the number of digits of your meter under Meter set-up. If a period is marked “Check this reading”, look at the reading for a typing mistake.

Use is the difference between two readings, so the comparison with your estimate starts with the second one.

Under More → Export and backup, save a backup file and send it to yourself. On the new phone choose “Restore from a backup file”. The app asks before it replaces data that is already there.

No. Your data is kept only on your device and we hold no copy of it. A backup file you saved earlier is the only way to bring it back.

More → Export and backup → “Delete everything”, or uninstall the app. Deleting everything cannot be undone.

Yes. On first launch choose “Try an example home first”. Its figures are invented.