What Are Billable Hours?
Billable hours are the time you spend working directly on client deliverables — tasks, projects, and services that can be invoiced. Every hour you log writing code for a client, drafting a legal brief, designing a wireframe, or consulting on strategy is a billable hour.
Non-billable hours cover everything else: internal meetings, admin work, business development, training, invoicing, and project management overhead. These are necessary to keep a business running, but they don’t generate revenue directly.
Understanding the distinction between billable and non-billable time is the foundation of profitability for freelancers, agencies, consultants, and law firms. If you don’t know how many hours you can actually bill, you can’t price your services accurately, forecast revenue, or identify where your time is leaking into unpaid work.
How to Calculate Billable Hours
The core formula is straightforward:
Billable Hours = Total Hours Worked − Non-Billable Hours
Your utilization rate tells you what percentage of your total working time is actually billable:
Utilization Rate = (Billable Hours ÷ Total Hours) × 100
For example, if you work 40 hours per week and spend 8 hours on admin, internal meetings, and business development, your billable hours are 32 and your utilization rate is 80%. That’s a strong number — most professional services firms target a utilization rate between 70% and 85%.
Below 70%, you’re likely spending too much time on overhead. Above 85% consistently, you may be under-investing in business development, training, or rest — which leads to burnout and stagnation. The sweet spot depends on your role: senior consultants and attorneys often target higher utilization, while managers and partners run lower because they spend more time on sales and mentoring.
Billable Hours Chart (6-Minute Increments)
Law firms, accounting practices, and many professional services firms bill in 6-minute increments — each block representing one-tenth of an hour. This convention allows precise billing for short tasks like phone calls, email reviews, and quick document edits without rounding up to the nearest quarter or half hour.
If you spend 18 minutes on a client call, you bill 0.3 hours. A 42-minute meeting is billed as 0.7 hours. Here’s the full reference:
| Minutes | Hours (Decimal) |
|---|---|
| 6 min | 0.1 hr |
| 12 min | 0.2 hr |
| 18 min | 0.3 hr |
| 24 min | 0.4 hr |
| 30 min | 0.5 hr |
| 36 min | 0.6 hr |
| 42 min | 0.7 hr |
| 48 min | 0.8 hr |
| 54 min | 0.9 hr |
| 60 min | 1.0 hr |
Many billing systems expect decimal hours, so memorizing this chart — or bookmarking this page — saves time when logging entries manually. The calculator above converts minutes to decimal hours automatically.
How to Track Billable Hours Automatically
Manual time tracking is the most common approach, and also the most error-prone. Studies consistently show that professionals who track time manually at the end of the day or week lose 10–15% of their billable time to forgotten tasks, rounded-down entries, and simple forgetfulness. Over a year, that’s thousands of dollars in revenue leakage.
The fix is automatic tracking tied to actual work. Corcava tracks billable hours automatically per task, per project, per client. Start a timer, work on a task, and your billable hours are logged with screenshots as proof of work. When the task is done, the hours are already allocated to the right client and project — no manual entry, no end-of-week guessing.
Because every time entry is linked to a task and a project, generating invoices with detailed hour breakdowns takes seconds instead of hours. Clients see exactly what they’re paying for, which reduces disputes and builds trust.
Stop Calculating — Start Tracking
Corcava tracks billable hours automatically per task, per project, per client — with screenshots as proof of work. Generate invoices from tracked time in seconds.
Start Tracking for Free →Free plan available. No credit card required.
Time tracking is just one piece of the puzzle.Learn how it fits into the bigger profitability picture →
New to billable hours? Read How to Track Billable vs Non-Billable Hours for a complete walkthrough.
Frequently Asked Questions
What is a good billable hours target?
Most professional services firms target 1,400 to 1,800 billable hours per year, which translates to a utilization rate of 70–85%. The right target varies by industry and role — attorneys at large firms often aim for 1,800+, while consultants and agency staff typically target 1,400–1,600. Freelancers should factor in time for sales, admin, and professional development when setting their own benchmarks.
How do law firms calculate billable hours?
Law firms typically use 6-minute increments, where each increment equals one-tenth of an hour. A 15-minute phone call is billed as 0.3 hours (rounded up to the next increment). Most firms have minimum billing increments — even a 2-minute email review may be billed as 0.1 hours. Attorneys log time entries throughout the day with descriptions of the work performed for each client matter.
What counts as non-billable hours?
Non-billable hours include internal meetings, administrative work, business development, training, timekeeping itself, and any work not directly attributable to a paying client. Marketing, proposal writing, hiring, and company culture activities also fall into this category. While essential to running a business, these hours don’t generate direct revenue and should be tracked separately to understand true profitability.
How can I increase my billable hours?
Automate administrative tasks wherever possible — time tracking, invoicing, and reporting are prime candidates. Batch internal meetings into dedicated blocks instead of scattering them throughout the day. Use time tracking software to identify where non-billable time is leaking, and set weekly budgets for non-billable activities. Delegating admin work and using templates for repetitive tasks also frees up more hours for client work.