EuroWattCalc
Break-even tool

Appliance upgrade payback calculator

Compare an existing appliance with a lower-power replacement and estimate how long electricity savings alone would take to recover the upgrade cost.

Reviewed 2 September 2026Simple payback — not investment advice

Old vs new

Use measured average power when you have it.

Energy saved / year—kWh
Money saved / year—electricity only
Simple payback—upgrade cost ÷ annual saving
5-year net—electricity saving − upgrade cost

This deliberately excludes maintenance, financing, lifespan, installation, resale value and non-energy benefits.

Simple payback formula

Annual kWh saved: (old watts − new watts) ÷ 1,000 × hours/day × days/year
Annual money saved: annual kWh saved × price per kWh
Payback: upgrade cost ÷ annual money saved

When this comparison is useful

Use it when two appliances deliver roughly the same job and you can estimate their average electrical input — a fridge-freezer replacing an older one of similar capacity, a heat pump tumble dryer replacing a vented dryer, or an LED-based appliance replacing an older lighting fixture. It is less useful when the replacement changes comfort, capacity, run time or fuel type, since those changes affect the value of the upgrade in ways electricity cost alone cannot capture.

A worked example

An old chest freezer draws roughly 200 W and runs for an estimated 8 hours of active compressor time a day, 365 days a year. A modern equivalent draws 90 W under the same conditions. At €0.30/kWh, the old unit costs around €175/year to run and the new one around €79/year — a saving of about €96/year. If the replacement costs €380, the electricity-only payback is roughly four years. Whether that is worthwhile depends on how many years of service you expect from the new appliance and what else factors into the decision.

Improve the estimate

For cycling appliances — fridges, freezers, washing machines, dishwashers — measured average power over a representative day is far more accurate than the nameplate maximum, because these devices spend much of their time at a lower draw or fully off between cycles. A plug-in energy meter left in place for 24–48 hours gives a realistic average.

If your tariff varies by time of day, use the rate that actually applies when the appliance runs, or a blended average if usage spans multiple rate periods — the time-of-use shift calculator can help model that split.

What this tool does not tell you

A short payback period is not, by itself, a recommendation to buy. It excludes the expected remaining lifespan of the existing appliance, the new appliance's own expected lifespan, installation and disposal costs, financing costs if the purchase is not paid in cash, and any non-energy benefits such as quieter operation, larger capacity or improved performance. Treat the payback figure as one input into a wider decision, not the whole of it.

Need to see where an upgrade matters most before committing to one? Start with the whole-home energy budget to find the appliance actually driving your bill.

Frequently asked questions

What counts as a fair like-for-like comparison?

Two appliances that do the same job at the same output — for example two fridges of similar capacity, or two washing machines with the same drum size. Comparing a small appliance with a much larger replacement will show a cost increase, not a saving, even if the replacement is more efficient per litre or per kilogram.

Should I use the nameplate wattage or a measured figure?

A measured average from a plug-in energy meter is more accurate for any appliance that cycles on and off, such as a fridge, washing machine or dishwasher. The nameplate figure is usually a maximum, not a typical draw.

Why does the calculator show no payback for some inputs?

If the replacement uses the same power or more than the existing appliance, there is no energy saving to recover the purchase cost, so no payback period can be calculated from electricity savings alone.

Does a short payback mean I should buy the replacement?

Not on its own. This tool estimates electricity savings only. It excludes the appliance's expected lifespan, installation cost, financing, maintenance, resale or disposal value of the old unit, and any non-energy benefits such as noise, capacity or convenience.

How should I estimate hours used per day for a cycling appliance?

Use total run time per day rather than hours plugged in. A fridge that cycles on for roughly eight hours in each 24-hour period should be entered as 8 hours, not 24, even though it is connected to power the whole day.

What if my electricity price changes by time of day?

Use the rate that applies when the appliance actually runs. If usage spans both a peak and an off-peak period, a blended average price will give a more realistic annual saving than either rate alone.