About the Billable Utilization Calculator
This billable utilization calculator measures what share of paid working time is spent on client work you can invoice. Enter available hours per week, billable hours per week, your target utilization, bill rate, working weeks per year and team size, and it returns the utilization rate, annual billable hours and revenue, and the revenue you are missing versus target.
Agencies, consultancies, law and accounting firms, IT services companies and freelancers use utilization to manage capacity, set hiring plans and check that pricing covers non-billable time such as sales, admin and training. The effective hourly rate shows what each paid hour actually earns once non-billable time is included.
Available hours are the hours a person is paid or expected to work (40 for full time). Use working weeks after holidays and leave — 46 to 48 is typical. Targets vary by role: delivery staff often aim for 70–85%, while managers and partners bill less.
With the default inputs, the billable utilization rate is 75%. Change any value above to recalculate instantly.
How to use the billable utilization calculator
- 1Enter weekly available hours and billable hours from timesheets.
- 2Set your target utilization for the role.
- 3Enter the average bill rate, working weeks per year and team size.
- 4Review utilization, annual revenue and the gap to target.
Formula and method
Utilization compares billable hours with the hours a person is available to work in the same period. Annual billable revenue multiplies weekly billable hours by working weeks, headcount and the bill rate, assuming all billable time is invoiced and collected at that rate.
The revenue gap is the extra billable hours needed to hit the target (target × available − billable) valued at the bill rate for the whole year and team. The effective rate divides revenue by all available hours, showing what each paid hour earns once non-billable time is counted.
- Billable hours
- Hours charged to clients per week
- Available hours
- Paid or expected working hours per week
- Rate
- Average hourly bill rate
Worked examples
Consultant billing 30 of 40 hours
30 ÷ 40 = 75% utilization. Over 48 weeks that is 1,440 billable hours, or $216,000 at $150 an hour. Reaching 80% would add 2 hours a week — $14,400 a year — and the effective rate across all paid hours is $112.50.
Agency team of five
Five people billing 26 of 40 hours run at 65%. Over 46 weeks they bill 5,980 hours, or $717,600. Hitting 75% (30 hours each) would add 4 hours × 46 weeks × 5 people × $120 = $110,400.
Above target
Billing 38 of 45 hours is 84.4% utilization, above the 80% target, so there is no revenue gap. At $200 an hour the year brings in $364,800, or $168.89 per available hour.
Frequently asked questions
How do you calculate utilization rate?+
Divide billable hours by total available hours for the same period and multiply by 100. For example, 32 billable hours in a 40-hour week is an 80% utilization rate.
What is a good billable utilization rate?+
Many professional services firms target 70–85% for delivery staff. Senior managers and partners usually bill less because of sales and management work. Sustained rates above 90% can lead to burnout.
What is the difference between utilization and realization?+
Utilization measures how much time is billable. Realization measures how much of the billable value is actually invoiced and collected after write-downs and discounts. Both affect profitability.
Should available hours include holidays and PTO?+
Either approach works if used consistently. This calculator uses weekly hours and working weeks per year, so reduce the weeks to exclude holidays and leave rather than lowering weekly hours.
How can I increase billable utilization?+
Reduce internal meetings and admin, keep a steady pipeline so staff are not idle between projects, track time accurately so billable work is not lost, and match staffing to forecast demand.