Planning tools

Test the decision before you spend the money.

The Savings Lab holds the tools that compare scenarios rather than calculate a single appliance: a whole-home budget, an upgrade break-even and a time-of-use tariff shift. Every result shows the formula behind it.

Whole-home energy budget

Add several appliances at once to see monthly kWh, monthly cost and which item drives the largest share.

Planner ⇄

Appliance upgrade payback

Compare an existing appliance with a lower-power replacement and see how long electricity savings take to cover the purchase.

Break-even ⏱

Time-of-use shift

Model moving part of a load from a peak rate to an off-peak rate and see the monthly and annual difference.

Tariff

How to use these three together

They answer different questions and work best in sequence. Start with the budget to find where the electricity actually goes, then test whether a change is worth paying for.

Find the driver. Build a whole-home budget from the appliances you genuinely run. The largest contributor is often not the one people expect.
Check the cheap change first. If your tariff has separate peak and off-peak rates, the time-of-use tool shows what shifting a load is worth before you buy anything.
Then test the purchase. Only when a device is both a large driver and cannot be shifted does an upgrade payback calculation become the useful next step.

What these tools deliberately exclude

All three model variable electricity consumption only. Standing charges, network fees, taxes, levies and any fixed monthly component sit outside the result, so a figure here will not match a bill total. They also exclude appliance lifespan, installation, financing, maintenance and resale value.

The inputs are yours to supply. We do not publish a single “current price” for each country because tariffs vary by supplier, contract and meter type — enter the rate printed on your own bill instead. The country pages explain where to find it.

Where the numbers come from

Nothing is sent to a server. Every calculation runs in your browser from the values you type. The exact formulas are published on each tool page and summarised in the methodology.