Six minutes doesn’t sound like much, until you multiply a rounding habit across every timekeeper on a legal team for a full year. A firm that consistently rounds up by even one increment per entry can add thousands of dollars in disputed fees, and a firm that rounds down loses real revenue on work it already did.
Most law firms and legal departments bill in tenths of an hour, which breaks each hour into ten 6-minute blocks. Here’s the full chart, along with what actually changes when you switch to a different increment size.
The Standard 6-Minute Billing Increment Chart
| Minutes Worked | Billable Increment |
| :—- | :—- |
| 1 to 6 minutes | 0.1 |
| 7 to 12 minutes | 0.2 |
| 13 to 18 minutes | 0.3 |
| 19 to 24 minutes | 0.4 |
| 25 to 30 minutes | 0.5 |
| 31 to 36 minutes | 0.6 |
| 37 to 42 minutes | 0.7 |
| 43 to 48 minutes | 0.8 |
| 49 to 54 minutes | 0.9 |
| 55 to 60 minutes | 1.0 |
To convert a block of time into a bill, multiply the increment by the hourly rate. A 24-minute task at a $300 hourly rate bills at 0.4, or $120.
Why Tenths of an Hour Became the Standard
Courts, insurance panels, and most large law firms settled on tenths of an hour because the math is simple and the increments are small enough to feel proportionate to short tasks. A quick phone call or a two-line email review still registers as billable time without inflating the invoice the way a 15-minute minimum would.
Federal fee guidelines, including those used for court-appointed counsel compensation, specify tenths-of-an-hour billing for exactly this reason. It keeps time entries auditable and comparable across timekeepers.
Where 10-Minute and 15-Minute Increments Still Show Up
Not every firm bills in six-minute blocks. Some insurance defense panels and smaller practices use 10-minute increments, dividing the hour into six parts instead of ten. Others, particularly in real estate and general practice, still bill in 15-minute quarter-hour blocks, which round more aggressively and can overstate short tasks.
The tradeoff is consistency versus simplicity. Six-minute increments produce more accurate bills but require more disciplined time entry. Quarter-hour billing is easier to track but rounds a five-minute call up to a full 0.25, four times what six-minute billing would charge.
Common Increment Errors That Cost Firms Real Money
The most frequent mistake isn’t picking the wrong increment size. It’s inconsistency: one timekeeper rounds every entry up to the next full increment out of habit, while another rounds down to avoid appearing to pad a bill. Neither approach reflects the actual time spent, and both create friction when a client’s billing department compares invoices across months.
A second common error shows up when legal teams manage a mix of internal staff and outside counsel or contract attorneys on different billing conventions. Without a standardized chart everyone references, the same 20-minute task gets billed as 0.3, 0.4, or a flat quarter hour depending on who did the work.
Standardizing Billing Across a Distributed Legal Team
This is less a math problem than a process problem once a legal department works with more than one outside provider. Standardizing on a single increment chart, and making sure every timekeeper, in-house or outsourced, applies it the same way, is exactly the kind of process gap legal operations work is built to close. LawFlex attorneys working through a flexible staffing engagement bill against the same standardized increment structure your in-house team already uses, so a distributed roster doesn’t turn into a distributed set of billing conventions.
FAQ
How many minutes is a 0.1 billing increment?
A 0.1 increment equals six minutes, since it represents one-tenth of a 60-minute hour.
What is the difference between 6-minute and 15-minute billing increments?
Six-minute increments divide an hour into ten parts and round more precisely, while 15-minute increments divide it into four larger blocks and round more aggressively, often overstating short tasks.
How do you calculate a bill using a billing increment chart?
Round the actual time worked up to the nearest increment on the chart, then multiply that decimal by the hourly rate. A 42-minute task at 0.7 and a $250 hourly rate bills at $175.
Why do most law firms use tenths of an hour instead of quarter hours?
Tenths of an hour produce smaller, more proportionate increments for short tasks like emails and calls, which keeps invoices closer to the actual time spent and easier to justify to clients.
Do all courts require billing in tenths of an hour?
Many federal fee guidelines, including those for court-appointed counsel, specify tenths-of-an-hour billing, but requirements vary by court and jurisdiction, so check the applicable local rule before finalizing time entries.
