Billable Hours Calculator

It sums every logged time entry, entered as either start and end times or a decimal duration per task, then subtracts your non-billable hours like breaks and admin. It applies your hourly rate to the result, so you get total billable hours, a utilization rate, and an invoice amount in one place.

Billable utilization is the share of your tracked time that you can bill. The formula is billable hours divided by total logged hours, times 100. If you log 8 hours and 6 are billable, your utilization is 75 percent. The calculator uses unrounded hours here, since rounding is a billing convention rather than time actually worked.

Rounding to 0.1 hour bills in 6-minute blocks, the tenth-of-an-hour method common in legal and consulting work. Rounding to 0.25 hour bills in 15-minute blocks, the quarter-hour method. This tool rounds your billable total to the nearest block you pick, or you can switch rounding off to bill exact time.

Each task duration is the end time minus the start time. If the end is earlier than the start, the calculator assumes the task ran past midnight into the next day and adds 24 hours. An end equal to the start counts as zero, not a full day.

The invoice equals your rounded billable hours multiplied by your hourly rate. For example, 6.75 billable hours at $80 per hour comes to $540. Leave the rate at 0 to track hours and utilization without producing an invoice figure.

No. This calculator gives a quick estimate of billable hours and invoice value for planning. It is not financial, tax, or legal advice. Confirm your rates, taxes, and rounding rules against your client agreement or a professional before you bill.