Convert minutes to decimal hours
Invoices multiply hours by a rate, so time has to be written as a decimal: 2 hours 15 minutes is 2.25 hours, not 2.15. Divide the minutes by 60 and add them to the whole hours.
| Minutes | Decimal hours | At 80.00 per hour |
|---|---|---|
| 6 | 0.1 | 8.00 |
| 10 | 0.167 | 13.36 |
| 15 | 0.25 | 20.00 |
| 20 | 0.333 | 26.64 |
| 30 | 0.5 | 40.00 |
| 40 | 0.667 | 53.36 |
| 45 | 0.75 | 60.00 |
| 50 | 0.833 | 66.64 |
Thirds of an hour do not divide exactly, so 20 minutes billed as 0.333 hours is slightly less than a third. If that matters, bill in 6- or 15-minute increments, which convert to exact decimals.
Billing increments and rounding
Many professionals bill in fixed increments: 6 minutes (a tenth of an hour) is common for lawyers and accountants, 15 minutes for consultants and tradespeople. State your increment and rounding rule in the contract and repeat it in Terms, as in the example, so the client can follow the arithmetic.
One line per task, date or rate
- List each task or day on its own line, with the date in the description if the client approves time by day.
- Use separate lines for different rates, such as standard hours, overtime or weekend work, or work by a junior and a senior colleague.
- Attach or reference a timesheet for longer periods; Notes is a good place for the timesheet reference.
- Bill expenses separately from time, at cost or at the markup you agreed.
The example in numbers
The editor example bills 2.5 + 4.25 + 1.5 = 8.25 hours at 80.00 an hour, a subtotal of 660.00. Because each task is on its own line, the client can see where the time went and approve the invoice without asking for a breakdown. If your rate changes part-way through a month, split the hours into two lines, one at each rate, rather than averaging them.
Clients are most likely to question round numbers on long periods, such as 40.00 hours for a month of ad hoc work. Specific entries, a timesheet reference and a short description of the outcome of each task answer most questions before they are asked.
Hourly work with a retainer
If the client pays a monthly retainer for a block of hours, invoice the retainer at the start of the month and any extra hours at the end, each on its own line. For project-based pricing with deposits and milestones, see the freelance invoice page.