About

Buying backup power is an expensive decision, and most of the advice out there comes from the people selling the batteries. Size My Backup exists to answer one question honestly: how much battery do you actually need?

We run a home battery system ourselves and measure what our own appliances draw. That is where the habits on this site come from: use real watts, respect surge, and do not buy capacity you will never use.

The calculator is free and needs no sign-up. If a model is listed, its specs were checked against the maker's own page, and the date of that check is kept with the data.

Size My Backup is run by MEC Industries LLC.