Time spent working that you can charge a client for.
Billable hours are units of time spent on work that you can charge a client for. For consultants, developers, and lawyers, billing by the hour means accurately tracking how much time is spent on client work — every hour logged is potential revenue.
Not all work is billable. Administrative tasks, business development, internal meetings, and learning time are typically non-billable. The key is having a clear agreement with clients about what counts as billable so there are no disputes at invoice time.
Accurate billable hour tracking requires starting and stopping timers at the right moments — which is harder than it sounds. Developers who work in deep focus sessions, switch context frequently, or use AI tools often forget to start timers. This is the main source of revenue leakage for freelancers.
Billable hours are typically rounded to the nearest increment (5, 10, 15, or 30 minutes) for invoice simplicity. Some consultants bill a minimum per engagement to cover context-switching overhead.
In ClockMe
ClockMe tracks billable hours per project with configurable hourly rates. Each time entry snapshots the billing rate at the moment it was created — so if you raise your rate next month, old entries are unaffected. Invoice PDFs show line-item entries with hours, rate, and total. Concurrent timers let you track multiple billable clients simultaneously.
Try ClockMe free →Assign time entries to specific projects. Billable projects have an hourly rate set; non-billable projects can be tracked at $0/hr. Reports in ClockMe separate hours by project so you can see billable totals clearly.
ClockMe's integration with Claude Code, Cursor, and other AI tools can auto-start timers when sessions open. For manual entries, ClockMe lets you add historical time entries with a start time and duration.
Rounding conventions vary by industry and client agreement. ClockMe supports rounding to the nearest 5, 10, 15, or 30 minutes. Many consultants round up to the nearest 15 minutes; legal billing often uses 6-minute (0.1 hour) increments.