A 6-minute billing increment is one tenth of an hour (0.1). Bill in 0.1 blocks: 1–6 minutes = 0.1, 7–12 = 0.2, up to 55–60 = 1.0. Check whether your engagement letter rounds up or to the nearest tenth.
Use the chart below when you convert clock time to billable tenths. Keep raw minutes for audits. Apply one rounding rule at invoice time.
Quick Answer
A 6-minute billing increment equals 0.1 hour. Most firms round each entry up to the next tenth. Some round to the nearest tenth. State the rule in your engagement letter so clients know how minutes become hours.
What is a 6-minute billing increment?
A 6-minute billing increment is a tenth of an hour. Sixty minutes divide into ten equal blocks of six minutes. Each block is 0.1 on the invoice.
Law firms, accountants, and consultants often bill this way. It is finer than 15-minute units and still simple to add. Clients can read 0.1, 0.2, and 0.3 without converting from minutes.
You still need a clear rounding rule. Exact time rarely lands on a sixth-minute boundary. Record the true duration first. Convert with one agreed method when you raise the bill. That habit matches good practice for how to calculate billable hours.
Six-minute units are common in time tracking for lawyers, where engagement letters often name the increment.
6-minute increment chart: minutes to tenths
Print or bookmark this table. The middle column rounds up to the next 0.1 hour. The right column rounds to the nearest 0.1 hour (half of a tenth, three minutes, rounds up).
| Minutes | Round up (0.1) | Round to nearest (0.1) |
|---|---|---|
| 1 | 0.1 | 0.0 |
| 2 | 0.1 | 0.0 |
| 3 | 0.1 | 0.1 |
| 4 | 0.1 | 0.1 |
| 5 | 0.1 | 0.1 |
| 6 | 0.1 | 0.1 |
| 7 | 0.2 | 0.1 |
| 8 | 0.2 | 0.1 |
| 9 | 0.2 | 0.2 |
| 10 | 0.2 | 0.2 |
| 11 | 0.2 | 0.2 |
| 12 | 0.2 | 0.2 |
| 13 | 0.3 | 0.2 |
| 14 | 0.3 | 0.2 |
| 15 | 0.3 | 0.3 |
| 16 | 0.3 | 0.3 |
| 17 | 0.3 | 0.3 |
| 18 | 0.3 | 0.3 |
| 19 | 0.4 | 0.3 |
| 20 | 0.4 | 0.3 |
| 21 | 0.4 | 0.4 |
| 22 | 0.4 | 0.4 |
| 23 | 0.4 | 0.4 |
| 24 | 0.4 | 0.4 |
| 25 | 0.5 | 0.4 |
| 26 | 0.5 | 0.4 |
| 27 | 0.5 | 0.5 |
| 28 | 0.5 | 0.5 |
| 29 | 0.5 | 0.5 |
| 30 | 0.5 | 0.5 |
| 31 | 0.6 | 0.5 |
| 32 | 0.6 | 0.5 |
| 33 | 0.6 | 0.6 |
| 34 | 0.6 | 0.6 |
| 35 | 0.6 | 0.6 |
| 36 | 0.6 | 0.6 |
| 37 | 0.7 | 0.6 |
| 38 | 0.7 | 0.6 |
| 39 | 0.7 | 0.7 |
| 40 | 0.7 | 0.7 |
| 41 | 0.7 | 0.7 |
| 42 | 0.7 | 0.7 |
| 43 | 0.8 | 0.7 |
| 44 | 0.8 | 0.7 |
| 45 | 0.8 | 0.8 |
| 46 | 0.8 | 0.8 |
| 47 | 0.8 | 0.8 |
| 48 | 0.8 | 0.8 |
| 49 | 0.9 | 0.8 |
| 50 | 0.9 | 0.8 |
| 51 | 0.9 | 0.9 |
| 52 | 0.9 | 0.9 |
| 53 | 0.9 | 0.9 |
| 54 | 0.9 | 0.9 |
| 55 | 1.0 | 0.9 |
| 56 | 1.0 | 0.9 |
| 57 | 1.0 | 1.0 |
| 58 | 1.0 | 1.0 |
| 59 | 1.0 | 1.0 |
| 60 | 1.0 | 1.0 |
For a quick conversion of hours and minutes to a decimal, use the free time to decimal calculator.
How do you convert minutes to billable tenths?
Round-up method
Divide minutes by six, then take the next whole tenth if there is any remainder. One to six minutes become 0.1. Seven to twelve become 0.2. This is the usual client-facing rule in many professional services firms.
Round-to-nearest method
Divide minutes by six and round to the closest tenth. Three minutes or more past a boundary move up. Less than three stay down. Example: 8 minutes is nearer 0.1 (6 minutes) than 0.2 (12), so nearest is 0.1. Fourteen minutes is nearer 0.2 than 0.3, so nearest is 0.2.
Worked examples
- 14 minutes, round up — next block is 18 minutes → 0.3 hours.
- 14 minutes, nearest — nearer 12 than 18 → 0.2 hours.
- 45 minutes — 45 ÷ 6 = 7.5 → 0.8 hours under both round-up and half-up nearest rules.
- 3 minutes, round up — 0.1 hours. Nearest with half-up is also 0.1.
- 2 minutes, round up — 0.1 hours. Nearest may be 0.0 unless you set a minimum 0.1.
Always disclose whether a minimum 0.1 applies on the shortest tasks.
Are 6-minute or 15-minute increments better?
| Increment | Size | Tenths / hour | Client feel | Best when |
|---|---|---|---|---|
| 6 minutes | 0.1 hour | 10 units | Finer, closer to actual time | Legal, advisory, mixed short tasks |
| 10 minutes | ~0.17 hour | 6 units | Less common | Niche firm preference |
| 15 minutes | 0.25 hour | 4 units | Coarser; small tasks inflate more | Simple retainers, fewer short calls |
Six-minute units usually look fairer for short calls and email. Fifteen-minute units are easier to explain but can overbill many tiny tasks. Ten-minute units sit in between and are less standard on invoices.
Pick one rule for the engagement. Put it in writing. Apply it the same way for every fee earner.
What mistakes cause billing increment disputes?
Common problems:
- Stacking round-ups on tiny tasks — ten separate two-minute notes can become 1.0 hour when each rounds to 0.1. Batch related work where your ethics rules allow.
- Undisclosed rounding — clients challenge bills when the letter is silent on increments.
- Mixed rules across the team — one person rounds up, another uses nearest, invoices look random.
- Editing raw time after the fact — keep exact minutes; change only the billed figure with a clear rule.
When billed hours and the invoice diverge, start with billable hours that do not match the invoice. Fix the rounding policy first.
How can software apply billing increments automatically?
Capture exact duration in your timer. Store seconds or minutes without rounding. Apply the engagement’s increment only when you build the invoice or export for billing.
That split keeps audit trails honest. You can show raw time if a client asks. You can still bill in tenths for the fee note.
Billing increments software should let you set 6-, 10-, or 15-minute rules per client or matter. Keito records exact durations and applies your billing increment when you invoice, so fee earners do not round by hand.
Key Takeaway
Record exact minutes, then apply one disclosed rounding rule (usually up to the next 0.1 hour) at invoice time.
Ready to bill in tenths without rounding by hand?
Keito records exact durations and applies your billing increment when you invoice.
Frequently Asked Questions
How many minutes is 0.1 of an hour?
Zero point one of an hour is six minutes. That is one 6-minute billing increment. On an invoice, 0.1 means one tenth of an hour of billable time under your rounding rule.
What is 0.3 hours in minutes?
Zero point three hours is 18 minutes. Under 6-minute increments, 0.3 covers the third tenth of the hour (minutes 13–18 when rounding up from shorter entries in that band).
Why do lawyers bill in 6-minute increments?
Lawyers often bill in tenths of an hour because six-minute units are fine enough for short calls and still easy to total. Many engagement letters name 0.1-hour increments so clients can read the fee note in standard units.
Is rounding up to the next 6 minutes legal?
Rounding up is common when the engagement letter discloses it and the practice follows professional conduct rules in your jurisdiction. It is a contract and ethics question, not a maths one. Confirm local rules and state the method in writing before you bill.
How do you write 45 minutes in tenths of an hour?
Forty-five minutes is 0.8 hours under 6-minute increments with round-up or half-up nearest rules. That is 45 ÷ 6 = 7.5 tenths, billed as 0.8. Put 0.8 on the invoice if that is your agreed method.
Should I use 6-minute or 15-minute billing increments?
Use 6-minute increments when you have many short tasks and want bills closer to actual time. Use 15-minute increments when work comes in larger blocks and simpler units help clients. Disclose the choice in the engagement letter either way.