wrolpi-help/docs/modules/inventory/summary.md

Summary

The Summary tab aggregates the inventory entirely on your device. Choose a field to Group by (such as Category) and a field to Sum (such as Size or Count). Quantities are summed with unit conversion and compacted to a sensible unit (for example, 16 oz + 1 lb is shown as 2 lb). If the inventory has a calories field, a Calories column shows the stored calories per group. Click any column header to sort.

Unlike the Items tab's search, the Summary always uses the whole inventory, so the totals here are never narrowed by a filter.