The honest formula is narrower than most teams assume:
- Billable utilization = billable hours ÷ available hours, counted only for billable people (engineers, designers, QA — not HR, sales or admin) and only on billable projects (client work, not internal tools).
- Available hours are net of time off. Someone on vacation for a week isn't "0% utilized" — they're unavailable. Counting PTO as available time makes good months look bad and hides real staffing problems.
For agencies and dev shops, a sustainable band is roughly 70–85%. Below 70%, revenue leaks through the bench; pushing past 85% for long stretches usually means no slack for estimates being wrong, internal improvements, or people simply being human.
Two common measurement mistakes: mixing overhead roles into the denominator (which permanently depresses the number and makes it useless as a signal), and tracking utilization only at month-end — by the time a low month shows up in a report, the hours are gone.
See the full guide: Billable utilization: what good looks like for an agency.
In Helia, utilization is computed from the capacity matrix — billable people on billable projects, net of approved time off — and updates the moment an allocation changes.