Free billable hours calculator

To calculate billable hours, add up your total hours worked on client work, remove the non-billable hours, and multiply the result by your billable rate. The core formula is: Billable Amount = Billable Hours × Hourly Rate.

However, this formula doesn't tell you where things might be going wrong or how you can improve profitability. For that, most professionals look at three other metrics:

• Utilization rate

  Billable Hours ÷ (Billable + Non-Billable Hours) × 100

  The share of your total work hours that are revenue-generating.

• Effective hourly rate

  Total Billable Revenue ÷ Total Hours Worked

  Your actual earnings per hour after accounting for all time worked — including non-billable hours. If you bill $150/h but spend a third of your workday on admin, your effective rate is closer to $100/h.

• Total billable revenue

  Billable Hours × Hourly Rate − Discount + Expenses

  The total invoiceable amount for a given period. Use it to benchmark against billable hour targets and assess profitability.

Not all work hours are created equal. Billable time covers the work you can charge clients for directly — executing deliverables, attending client meetings, conducting research, reviewing documents. Non-billable time covers everything that keeps your business running but doesn't appear on an invoice: internal meetings, administrative tasks, new business pitches, employee training, and time spent managing timesheets themselves.

The distinction matters enormously for profitability. If you spend 10 hours on client work and 6 hours on administrative work in a workweek, your utilization rate is 63% — meaning over a third of your available capacity is generating zero billable value.

Many professionals — especially those still using spreadsheets or piecing together timesheets at the end of the day — systematically undercount non-billable hours. The result is an inflated utilization rate, a distorted view of profitability, and billing rates that don't reflect what the work actually costs. Switching to automatic time tracking software solves this at the source: you log billable and non-billable work as it happens, and the split is always accurate.

Law firms and legal professionals have long used 6-minute billing increments — tenths of an hour — as the industry standard for tracking time entries. The logic is straightforward: whole-hour billing loses money on short tasks like a 4-minute email or an 8-minute phone call, while per-minute tracking creates unmanageable administrative overhead. Six-minute increments hit the sweet spot.

Why it matters for revenue

Billable hour targets in large law firms typically range from 1,800 to 2,200 hours per year. Meeting those targets requires recording time entries as they happen — relying on memory to reconstruct them at the end of the day leads to systematic undercounting. Missing even 15 minutes of billable time per day adds up to thousands in lost revenue across a year at standard billing rates.

The CJA billing standard

The 6-minute billing tool in this calculator is modeled on the CJA billing increment chart published by the U.S. District Court for the Northern District of California — the same standard used across federal courts and most private law firms. Each tenth of an hour equals exactly 6 minutes, and any task is rounded up to the nearest tenth regardless of how short it was.