Quick answer

Lawyers bill in tenths of an hour, where six minutes equals 0.1 hours, because it converts cleanly to money and is fair to the client. The hard part is not the math; it is capturing every increment as it happens instead of rebuilding the day from memory and quietly losing hours.

This guide is written for attorneys, paralegals, and law firms billing by the tenth of an hour who want time tracking to support better planning, billing, reporting, and project decisions.

Why lawyers bill in six-minute increments

Sixty minutes divides into ten six-minute blocks, so each block is exactly 0.1 hours. That clean division is the whole reason the convention exists: it converts to money with simple multiplication and it does not overcharge a client for a two-minute email the way a fifteen-minute minimum would. A 42-minute task is seven increments, or 0.7 hours, at your rate.

Some firms bill in quarter-hour increments instead, rounding to 0.25 hours. That is easier to eyeball but harder to justify, because a three-minute call billed as fifteen minutes is the kind of line item that gets challenged. Six-minute increments are the industry default precisely because they are the most defensible when a client reads the invoice line by line.

  • 1 to 6 minutes bills as 0.1 hours
  • 7 to 12 minutes bills as 0.2 hours
  • 13 to 18 minutes bills as 0.3 hours
  • A full hour is 1.0, made of ten increments
  • Multiply the decimal by your rate to get the line amount

Track contemporaneously or lose the hours

The single biggest source of lost legal revenue is not undercharging; it is untracked work. A phone call handled between two other tasks, a quick document review, a client email answered from the car: each is a real increment, and each vanishes if you wait until end of day to write your time. Studies of manual recall put the loss at 20 to 40 percent of actual work.

The fix is to start a timer or write the entry the moment the task begins, not the moment you remember it existed. Every increment you capture as it happens is money you were always owed. The goal is not to work more; it is to stop giving away the work you already did because a call interrupted the note you meant to write.

Writing entries that survive a client's review

A billable entry has to do two jobs: record the time and explain the work to someone who was not there. "Research, 1.2 hours" invites a dispute. "Reviewed opposing counsel's motion and drafted response outline, 1.2 hours" gets paid. The description is not paperwork; it is the difference between an invoice the client approves and one they call about.

Avoid block billing, where several tasks are lumped into one large undifferentiated entry. Clients and, in disputed matters, courts read block billing as padding, even when the hours are real. Break the work into its actual increments with a plain description of each, written while the detail is still fresh enough to be specific.

What a realistic billable target looks like

Firms often quote annual billable targets of 1,800 to 2,000 hours. What that hides is the gap between hours worked and hours billed. Reaching 1,900 billable hours usually means working far more, because a large share of any legal day goes to non-billable work: business development, administration, training, and firm management that no client pays for.

This is worth being honest about internally, because a target set as if every worked hour were billable produces burnout and padded time, not revenue. Track non-billable work in the same system as billable work. Seeing where the non-billable hours go is the only way to decide which of them to cut, delegate, or systematize.

When a general time tracker is not enough

A tool like Zeitio handles the core of legal time tracking well: capturing increments as they happen, tying each entry to a matter and task, keeping billable and non-billable work in one place, and turning reviewed time into invoice-ready records. For solo attorneys, small firms, and paralegal teams that mainly need clean time capture and billing, that covers the job.

It is not, however, a trust-accounting or legal-specific compliance system. If your firm needs IOLTA trust management, LEDES-format e-billing for insurance-defense clients, or conflict-checking built into the same tool, use dedicated legal practice-management software for those functions. Be clear about which problem you are solving: general time capture and invoicing, or regulated legal accounting. They are different tools.

Where Zeitio fits

Zeitio helps teams connect tracked hours to clients, projects, tasks, reports, approvals, and invoices so time data becomes useful business context instead of another spreadsheet.

Start with simple time entries, review them weekly, and use the data to improve project planning, billing accuracy, and team workload decisions.

Compare Zeitio pricing or create a workspace to try the workflow.

Further reading

FAQs

Why do lawyers bill in six-minute increments?

Sixty minutes divides evenly into ten six-minute blocks, so each block is exactly 0.1 hours. That converts to a dollar amount with simple multiplication and is fairer to clients than a longer minimum, which is why it became the legal industry default.

How do you convert minutes to billable increments?

Divide the minutes worked by six and round to the nearest tenth. 42 minutes is seven increments, or 0.7 hours. Then multiply the decimal by your hourly rate to get the line amount.

What is block billing and why avoid it?

Block billing lumps several tasks into one large undifferentiated time entry, such as "various matters, 3.5 hours." Clients and courts often read it as padding even when the hours are genuine, so break work into its actual increments with specific descriptions.

How many billable hours should an attorney target?

Firms commonly set annual targets of 1,800 to 2,000 billable hours, but reaching that requires working considerably more because of non-billable business development, admin, and training. Tracking both types of time is the only way to manage the gap.

Can Zeitio be used for legal time tracking?

Zeitio handles the core: capturing increments as they happen, tying them to matters and tasks, and turning reviewed time into invoices. It is not a trust-accounting, IOLTA, or LEDES e-billing system, so firms needing regulated legal accounting should pair it with dedicated legal software.