Billable Hours Chart: 6-Minute Increments Converted to Tenths of an Hour

Most law firms bill time in tenths of an hour. One tenth (0.1) equals 6 minutes, so a 1-hour block is split into 10 billing units. A billable hours chart shows how to turn the minutes you actually worked into those tenths.

The chart is easy to use. The questions come up around it. Do you round up or round to the nearest tenth? Do you round each entry or the day's total? What do clients and insurers allow? The answers can change a bill more than most firms expect.

Below is the full chart, a reverse chart for tenths back to minutes, worked dollar examples, and the rules that apply to billing in tenths.

What Is a Billable Hours Chart?

A billable hours chart is a reference table that converts minutes worked into billable units, usually tenths of an hour. Lawyers, paralegals and billing staff use it to record time entries the same way every time, so invoices are consistent and easy for clients to check.

Most firms bill in 6-minute increments. Some use 10- or 15-minute increments, which are covered further down.

Billable Hours Chart: Minutes to Tenths of an Hour

This is the standard 6-minute increments chart. Any time within a range is billed as that range's tenth.

For time over an hour, bill the full hours plus the tenth for the leftover minutes. For example, 1 hour and 20 minutes is 1.0 + 0.4 = 1.4 hours.

Federal courts use this same chart for court-appointed attorneys under the Criminal Justice Act. The U.S. District Court for the Northern District of California publishes it as its billing increment chart for minutes to tenths of an hour, with the instruction that time "should be reported in tenths of an hour."

Tenths of an hour to minutes chart

Use this when you need to read an invoice or time report the other way.

To convert any decimal to minutes, multiply by 60. For example, 2.7 hours is 2 hours and 42 minutes.

How to Convert Minutes to Tenths of an Hour

To convert minutes to tenths of an hour, divide the minutes by 6 and round to a whole number. That number is your tenths. For example, 25 minutes ÷ 6 = 4.17. Rounded up, that's 5, which is 0.5 hours.

How you round matters. Firms use one of two methods, and the method should be stated in the engagement letter or the client's billing guidelines.

Round up to the next tenth

This is the method the chart above uses, and it's the most common one in law firms. Any part of a 6-minute block counts as the full block, so 1 minute is billed as 0.1 and 7 minutes as 0.2.

The upside is simple math and a minimum charge for every task. The downside is that short tasks get rounded up the most. Three emails that take 1 minute each are billed as 0.3, which is 18 minutes for 3 minutes of work.

Round to the nearest tenth

Some clients and firms round to the nearest tenth instead. Time is rounded down when it's closer to the lower tenth and up when it's closer to the higher one. Here's how that works:

• 1 to 2 minutes: 0.0, so the time isn't billed
• 3 to 8 minutes: 0.1
• 9 to 14 minutes: 0.2
• 15 to 20 minutes: 0.3
• 21 to 26 minutes: 0.4

The same pattern continues every 6 minutes, so 57 to 60 minutes is 1.0. Clients see this as fairer, because it averages out over many entries instead of always rounding up.

Why Do Lawyers Bill in 6-Minute Increments?

Lawyers bill in 6-minute increments because 6 minutes is exactly one-tenth of an hour, which makes the math simple. Multiplying 0.4 hours by an hourly rate is easier than working with 24 minutes or 0.333 hours.

There are other reasons too:

• It captures short tasks. Phone calls, emails and quick document reviews add up over a day. At 0.1 each, they get billed instead of lost.
• Clients and courts expect it. Insurance carriers ask for it in their billing guidelines. The Hartford's guidelines for panel counsel say, "Actual time should be entered in tenths of an hour." Federal courts use tenths for CJA vouchers.
• It fits e-billing. Electronic billing formats like LEDES report time as decimal hours next to UTBMS task codes. Tenths drop straight into those files.

6-Minute vs. 10-Minute vs. 15-Minute Billing Increments

The bigger the increment, the more a short task costs the client. Here's a 4-minute phone call billed at $300 an hour under each system:

• 6-minute increments: billed as 0.1 hours, which comes to $30
• 10-minute increments: billed as 0.17 hours, which comes to $51
• 15-minute increments: billed as 0.25 hours, which comes to $75

The same 4 minutes of work costs 2.5 times more under 15-minute billing than under 6-minute billing. That's why many corporate clients and insurers don't accept quarter-hour billing.

Ten-minute decimals are hard to read on an invoice, which is one reason few law firms use them.

How to Calculate Billable Hours From Tenths of an Hour

To calculate a bill, multiply the billable time in tenths by the hourly rate.

A few examples:

• 0.3 hours at $250 an hour = $75
• 0.8 hours at $350 an hour = $280
• 2.4 hours at $425 an hour = $1,020

Your hourly rate drives every one of these numbers. Our guide to lawyer hourly rates covers how firms set them.

Should you round each time entry or the daily total?

This is where the biggest differences show up, and most billing charts skip it.

Say a lawyer handles five quick tasks on a matter in one day, each taking 2 minutes:

• Rounding each entry up: 5 entries × 0.1 = 0.5 hours. At $400 an hour, that's $200.
• Rounding the daily total: 10 minutes total = 0.2 hours. At $400 an hour, that's $80.

Same work, same rate, and a $120 difference. Rounding each entry is standard when tasks are separate and need their own descriptions. But if a client sees ten 0.1 entries in one day for a few emails, expect questions. Whatever you choose, apply it the same way on every matter.

Billing Rules for Tenths of an Hour

There's no law requiring 6-minute increments. Ethics rules and client guidelines still control how the time is recorded and billed.

Bill only the time you actually work

ABA Model Rule 1.5(a) says a lawyer can't charge or collect an unreasonable fee. ABA Formal Opinion 93-379, from 1993, went further on hourly billing. It said a lawyer can't bill more time than they actually spent, and can't bill two clients for the same hours. Rounding up to a minimum increment is generally accepted. Adding time that wasn't worked is not.

Follow the client's billing guidelines

Corporate clients and insurers often send outside counsel guidelines that set the increment, reject block billing, and refuse charges for routine tasks. The Hartford's guidelines, for example, say block billing "is not acceptable" and treat routine scheduling as overhead. If a client's guidelines and your firm's default settings differ, the client's guidelines win on that matter.

Record time when you do the work

The chart only helps if the minutes going in are accurate. Time reconstructed at the end of the week is usually a guess. Our guide on how to track billable hours covers ways to capture time as you work.

Track Time in Tenths Without the Math

Frequently Asked Questions About Billable Hours Charts

How many minutes is 0.1 of an hour?

0.1 of an hour is 6 minutes. In legal billing, 0.1 is the smallest standard billing increment, so any task from 1 to 6 minutes is usually billed as 0.1.

How do you convert minutes to tenths of an hour?

Divide the minutes by 6 and round up to the next whole number. That number is your tenths. For example, 20 minutes ÷ 6 = 3.33, which rounds up to 4, or 0.4 hours. Some firms round to the nearest tenth instead, which gives 0.3 for the same 20 minutes.

Is 1 minute billed as 0.1 hours?

Under the round-up method, yes. Any work from 1 to 6 minutes is billed as 0.1, or 6 minutes. Under the nearest-tenth method, 1 or 2 minutes rounds down to 0.0 and isn't billed.

Do lawyers round up billable time?

Most law firms round up to the next 6-minute increment. Rounding up to a minimum increment is generally accepted, but billing time that wasn't worked is not. Some clients require rounding to the nearest tenth instead.

What is 0.3 billable hours in minutes?

0.3 billable hours is 18 minutes. Multiply any tenth by 6 to get minutes. For example, 0.5 is 30 minutes and 0.8 is 48 minutes.

What is the difference between 6-minute and 15-minute billing increments?

Six-minute increments split an hour into 10 units of 0.1. Fifteen-minute increments split it into 4 units of 0.25. A 4-minute call is billed as 0.1 hours under 6-minute billing and 0.25 hours under 15-minute billing. That's 2.5 times more for the same work.

How do you calculate a bill from tenths of an hour?

Multiply the billable time by the hourly rate. For example, 0.7 hours at $300 an hour is $210.

Can a client refuse to pay minimum billing increments?

A client can set its own billing rules in the engagement letter or its outside counsel guidelines, including the increment and which short tasks it will pay for. If those terms were agreed before the work started, the firm should bill by them.