Work out untagged resource cost instantly with clear inputs, formula shown and shareable results.
Untagged resources are a proxy for unowned ones, and a meaningful fraction of them are orphans left behind by deleted projects, failed deployments and departed engineers. Estimating spend from the resource share is rough but sufficient to justify a cleanup: at 15 percent untagged and a quarter of those orphaned, over 5,000 a month is being spent on nothing.
Untagged spend
untagged share = untagged resources / total; untagged spend = total spend x share; orphan spend = untagged spend x orphan share
Check for zero network traffic, no attached compute, no recent API access and no recent logins. Snapshot before deleting so a mistake is recoverable.
Because nothing deletes them. Resources created outside infrastructure-as-code have no lifecycle owner, which is the strongest argument for creating everything declaratively.