Billable Time + Rounding
Round worked minutes to billing increments (6, 15, 30, or 60 minutes) and calculate invoice amounts.
Round worked minutes to billing increments (6, 15, 30, or 60 minutes) and calculate invoice amounts.
Billable time rounding converts the actual minutes spent on client work into the standard units used on an invoice. Attorneys commonly bill in tenths of an hour (6-minute increments), while accountants, consultants, and freelancers often use quarter hours (15 minutes), half hours, or full hours. A 22-minute call, for example, becomes 24 minutes (0.4 hours) in 6-minute increments rounded up, or 30 minutes (0.5 hours) in 15-minute increments rounded up.
Two choices drive the result: the increment size and the rounding direction. Rounding up always bills the next full increment, rounding to the nearest increment balances small overages and shortfalls, and rounding down favors the client. Engagement letters and client contracts often specify both, so check the agreement before choosing a method. Rounding is applied to each time entry, which means many short tasks rounded up separately can add noticeably more billable time than one combined entry. Hourly rate only affects the dollar figure, not the rounded time.
To use the calculator, enter the minutes worked, pick an increment from the Round to menu (6, 15, 30, or 60 minutes), and choose Round up, Round nearest, or Round down. Optionally enter an hourly rate in dollars. Press Calculate to see the billable time in minutes, the same amount in decimal hours to two places, and, when a rate is entered, the invoice amount for that entry. For example, 37 minutes at 15-minute increments rounded up gives 45 minutes (0.75 hours), or $112.50 at $150 per hour. Results are estimates; your billing agreement controls the final invoice.
Round up always bills the full next increment. Round nearest is fairest. Round down gives a discount.
Many law firms bill in 0.1-hour (6-minute) increments — the most common legal billing unit.
Yes — enter your hourly rate and the result includes the invoice amount.
Results are estimates for planning purposes only.
Billable time rounding converts raw minutes worked into billing increments — 6-minute, 15-minute, 30-minute, or hourly units — depending on your profession and client agreement.
The three rounding methods are:
Round up (ceiling): Always round to the next full increment. 7 minutes becomes 12 minutes (2 × 6-min units). Standard in legal billing.
Round nearest: Round to the nearest increment. 7 minutes becomes 6 minutes (1 unit), 10 minutes becomes 12 minutes (2 units). Fairest to both parties.
Round down (floor): Always round down. 11 minutes becomes 6 minutes. Sometimes used to show goodwill to long-term clients.
| Profession | Common increment | Minimum billing | Notes |
|---|---|---|---|
| Attorney / Law firm | 6 min (0.1 hr) | 6 minutes | Industry standard in legal |
| CPA / Accountant | 15 min (0.25 hr) | 15 minutes | Varies by firm |
| Consultant | 15 or 30 min | 30–60 minutes | Often project-based |
| Freelance designer | 15 or 30 min | None to 1 hour | Negotiated per project |
| IT / Tech support | 30 min | 30–60 minutes | Block billing common |
| Freelance writer | 1 hour | 1 hour | Often flat-rate instead |
| Minutes worked | 0.1 hr increments (legal) | 0.25 hr increments (15 min) | Decimal hours |
|---|---|---|---|
| 5 min | 0.1 hr | 0.25 hr | 0.08 |
| 10 min | 0.2 hr | 0.25 hr | 0.17 |
| 15 min | 0.3 hr | 0.25 hr | 0.25 |
| 20 min | 0.4 hr | 0.25 hr | 0.33 |
| 30 min | 0.5 hr | 0.50 hr | 0.50 |
| 45 min | 0.8 hr | 0.75 hr | 0.75 |
| 50 min | 0.9 hr | 0.75 hr | 0.83 |
| 55 min | 1.0 hr | 1.00 hr | 0.92 |
Most law firms bill in 6-minute increments (0.1 hours). So 7 minutes of work is billed as 0.2 hours (12 minutes), and 13 minutes is billed as 0.2 hours. The standard is to round up to the next increment.
15-minute increments (quarter hours) are the most common for consultants, accountants, and freelancers. Legal billing uses 6-minute (0.1 hour) increments. IT and tech professionals often use 30-minute minimums.
Rounding up always benefits you as the service provider. Rounding to nearest is fairer to the client. The right choice depends on your industry, client relationships, and engagement terms. Always use the method specified in your contract.
Record start and end times for each task. Subtract start from end to get raw minutes. Apply your rounding rule. Divide by 60 to get hours. Multiply by your hourly rate for the dollar amount.
Some professionals charge a minimum regardless of time spent — often 15 or 30 minutes. If a 5-minute phone call triggers a 15-minute minimum, the client is billed for 15 minutes even though only 5 were spent.
Convert the partial hour to decimal format: 15 minutes = 0.25, 30 minutes = 0.50, 45 minutes = 0.75. Multiply your hourly rate by the decimal. For example, $150/hour × 0.25 = $37.50 for 15 minutes.
Use the 1099 Hourly Rate Calculator on this site to estimate what you need to charge based on your desired income, expenses, and tax obligations. Most freelancers undercharge when they don't account for taxes, benefits, and non-billable time.
With Round nearest, an exact halfway point rounds up. For example, 3 minutes at 6-minute increments becomes 6 minutes (0.1 hours), and 45 minutes at 30-minute increments becomes 60 minutes.
Most professionals don't bill in exact minutes — they round to a standard increment. Enter your worked time, choose your rounding increment and method, and the calculator shows your billable time and invoice amount.
| Profession | Standard increment | Example: 22 minutes becomes |
|---|---|---|
| Attorney / Law firm | 6 minutes (0.1 hr) | 0.4 hours (24 min) |
| CPA / Accountant | 15 minutes (0.25 hr) | 0.25 or 0.5 hours |
| Consultant | 15 or 30 minutes | 0.25 or 0.5 hours |
| Freelance designer | 15 or 30 minutes | 0.25 or 0.5 hours |
| IT / Tech support | 30 minutes | 0.5 hours |