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Billing Increments for Attorneys: 0.1 vs 0.25 Hours and How Software Handles Rounding

Last updated: March 21, 2026

TLDR

Most US law firms use 0.1-hour (6-minute) billing increments. The standard exists because it balances accuracy for clients with tractability for attorneys — but the choice of increment directly affects annual revenue in ways most attorneys underestimate.

DEFINITION

Billing increment
The minimum unit of time an attorney bills for a given task. A 0.1-hour increment means any task under 6 minutes is billed as 0.1 hours (6 minutes). A 0.25-hour increment means any task under 15 minutes is billed as 0.25 hours (15 minutes).

DEFINITION

Rounding convention
Whether a billing increment rounds up, rounds to nearest, or rounds down. Most legal billing software rounds up to the nearest increment — a 7-minute task at 0.1-hour increments is billed as 0.2 hours (12 minutes), not 0.1.

DEFINITION

Contingency matter
A matter where the attorney is paid a percentage of the recovery rather than an hourly rate. Time tracking on contingency matters is still valuable for internal profitability analysis even though it is not billed directly to the client.

Where the 6-minute standard came from

Before the 1960s, most legal work was billed on flat fees or hourly rates without granular time records. Attorneys sent bills that said “services rendered: $200.” Clients paid them — or they did not.

The billable hour became the dominant model partly for practical reasons and partly because large firms found it aligned incentives (more hours worked, more revenue). By the 1970s, large law firms were formalizing their time tracking systems, and the question of what increment to use became a real operational decision.

The 0.1-hour increment won because it hit a practical optimum. Quarter-hour billing (0.25 hours) is simple — you only need to know which 15-minute block a task fell into — but it overstates short tasks dramatically. A 3-minute phone call billed at 0.25 hours is billed as 15 minutes: five times the actual time. Sixth-of-an-hour (0.1) billing means the same call is billed as 6 minutes — overstated, but modestly.

Tenth-of-an-hour billing spread from large firms to small firms and solo practitioners over the following decades. Today it is the default in every major legal billing software package and the increment most courts expect to see in fee petitions.

0.1 hours vs 0.25 hours: the practical tradeoffs

The 0.1-hour increment is more accurate, generates fewer client complaints, and is more defensible in fee disputes. The 0.25-hour increment is slightly simpler to apply mentally if you are not using software timers.

For any attorney using practice management software — which is the standard — the manual calculation advantage of 0.25-hour billing disappears entirely. The software handles the rounding automatically. The 0.25-hour minimum billing on short tasks then becomes a pure negative: clients who review their itemized bills will notice that a 4-minute call was billed as 15 minutes, and they will ask about it.

Courts have also pushed back on larger increments in fee petitions. In cases where fee awards are subject to court approval (class actions, statutory fee-shifting cases, guardian ad litem work), courts regularly reduce fees where the billing increment applied is found to inflate short tasks unreasonably. Using 0.1-hour increments is the more conservative and defensible practice.

Some firms use 0.25-hour billing specifically for flat-rate tasks or low-complexity communications, while using 0.1-hour increments for everything else. This hybrid approach is common but creates administrative overhead — you have to track which matters use which increment — without a clear benefit over simply standardizing on 0.1 for all hourly work.

The ethics of billing increments: Model Rule 1.5

ABA Model Rule 1.5 requires that attorney fees be reasonable. The rule does not specify a billing increment, but comment and case law make clear that the reasonableness standard applies to how time is measured, not just what rate is charged.

The billing increment affects reasonableness in two ways. First, a large minimum increment applied to genuinely short tasks inflates the amount billed relative to the actual time spent. Second, rounding-up conventions (billing a 7-minute task as 0.2 hours rather than 0.1 hours) compound this effect across many entries.

Most ethics opinions that have addressed billing increments accept 0.1-hour billing as per se reasonable. Larger increments receive more scrutiny. Some state bars have issued opinions specifically cautioning against increments that result in systematic overbilling on short tasks.

The practical guidance: use 0.1-hour increments, round up (not down) to the nearest increment, and make sure your time descriptions justify the time spent. A 0.2-hour entry for a 7-minute task is defensible if the description explains what happened in those 7 minutes. A 0.25-hour entry for a 3-minute call with the description “call with client” is not.

How rounding works in practice

When you stop a timer in legal billing software, the software converts the elapsed time to hours and rounds to the nearest increment. With 0.1-hour (6-minute) increments, rounding-up works like this:

  • 1–6 minutes: 0.1 hours
  • 7–12 minutes: 0.2 hours
  • 13–18 minutes: 0.3 hours

With 0.25-hour increments:

  • 1–15 minutes: 0.25 hours
  • 16–30 minutes: 0.5 hours

The 0.1-hour column inflates short tasks by at most 5 minutes. The 0.25-hour column inflates short tasks by up to 14 minutes. Over a full week of brief communications — email responses, short calls, quick reviews — the difference in billed time can be material, and the difference in client perception is significant.

Legal billing software sets this rounding automatically. In CaelusLaw, Clio, MyCase, and PracticePanther, you configure your increment preference once at the firm or matter level, and all timer-generated entries round accordingly. Manual entries round when you save them.

The increment is not where most revenue is lost

The billing increment matters, but it is not where most small firm attorneys lose billable time. The bigger problem is tasks that never get recorded at all.

An attorney who handles a dozen short communications in a day — emails, calls, quick document reviews — and reconstructs their timesheet from memory at 5 PM will forget several of them. At 0.1-hour per task, each forgotten entry costs $30–$60 at typical solo billing rates. Over 200 working days, that adds up.

Contemporaneous tracking — recording a time entry within minutes of completing a task, or using a running timer — captures entries that reconstruction misses. The research on this is consistent: attorneys who track contemporaneously bill 10–30% more than those who reconstruct from memory. That gap dwarfs any revenue difference between 0.1-hour and 0.25-hour increments.

The most effective billing increment is whichever increment your software applies automatically when you are tracking time consistently. For most attorneys, that is 0.1 hours, using timers built into their practice management software, with entries reviewed before the invoice goes out.

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What billing increment should attorneys use?

0.1 hours (6 minutes) is the standard at most US law firms and is the recommended default. Some firms use 0.25 hours (15 minutes), which is simpler to calculate manually but rounds up short tasks significantly and generates client complaints on itemized bills. ABA guidelines do not mandate a specific increment, but 0.1 is the de facto standard for hourly billing. Using a larger increment may invite scrutiny if fees are ever reviewed by a court.

Is 6-minute billing standard for attorneys?

Yes, 0.1-hour increments are standard at most US firms. The 6-minute increment became dominant in the 1970s when billable hour tracking replaced flat fees as the primary billing model at large firms and eventually spread to the broader market. It provides enough granularity that clients can verify entries while remaining practical for attorneys to track without a stopwatch.

How do billing increments affect revenue?

A firm using 0.25-hour increments bills 15 minutes minimum for a 2-minute phone call. This generates more per-call revenue but also more client disputes. A firm using 0.1-hour increments bills 6 minutes for the same call — more defensible to clients, slightly less per short task. The real revenue impact is not the increment itself but whether tasks are captured at all. End-of-day time reconstruction at any increment loses 10–30% of billable time compared to contemporaneous tracking.

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Frequently Asked Questions

Can I bill in 0.5-hour increments?
Technically yes, but it will generate client complaints and may not hold up to scrutiny. A 0.5-hour minimum means a 5-minute phone call is billed as 30 minutes. Most clients find this unreasonable. More importantly, courts reviewing fee awards have reduced or denied fees where minimum billing increments were found to be excessive. The larger the increment, the harder it is to defend on an itemized bill.
Do flat-fee matters need billing increments?
Flat-fee matters do not generate invoices based on time, so the increment does not affect what clients pay. But tracking time internally on flat-fee matters — marked non-billable — is valuable for measuring profitability and pricing future flat-fee work. For internal tracking purposes, use the same 0.1-hour increment your hourly matters use so the data is consistent.
Does billing software handle increment rounding automatically?
Yes. All legal billing software — including CaelusLaw, Clio, MyCase, and PracticePanther — applies rounding automatically based on the increment you configure. You set the increment once, either globally or per matter, and the software rounds each time entry when you stop a timer or save a manual entry. You never have to calculate the rounding yourself.
What increment does Clio use by default?
Clio's default billing increment is 0.1 hours. You can change it per-matter or globally in account settings. Most other legal billing tools default to the same 0.1-hour standard.

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