Detention math is simple, but small differences in how you count time can change the amount by an hour or more. Getting it right, and showing your work, is what keeps claims from bouncing.
The formula
Billable time = (Departure − Arrival) − Free time
Detention pay = Billable time × Hourly rateUse the arrival and departure times from your ELD or GPS, and the free time and rate from the rate confirmation for that load.
Example 1: straightforward
- Arrival 07:50, departure 13:12: total dwell 5 hrs 22 min
- Free time 2 hrs: billable 3 hrs 22 min (3.37 hrs)
- Rate $60/hr: 3.37 × $60 = $202.00
Rounding rules change the answer
Rate cons often state how partial hours are billed. The same 3 hrs 22 min becomes:
- Exact minutes: $202.00
- 15-minute increments, rounded up: 3.5 hrs = $210.00
- 15-minute increments, rounded down: 3.25 hrs = $195.00
- Full hours only: 3 hrs = $180.00
Always apply the method in the rate con. If it is silent, bill exact minutes and say so on the invoice. Rounding in your favor without a basis invites a dispute over the whole claim.
Things that change the clock
- Appointment time. Many rate cons start free time at the appointment, not at arrival, if the driver arrives early. Arriving late can void detention entirely.
- Caps. Some rate cons cap detention per stop or per day, or switch to a layover rate after a set number of hours. See detention vs. layover vs. TONU.
- Multiple stops. Free time usually applies per stop, so calculate each stop separately.
- Time zones. Check that arrival and departure are in the same zone, especially when your ELD reports in home-terminal time.
Show the math on the invoice
Write out total dwell, free time, billable time, rate, and total. A broker's AP team can approve a claim they can verify in ten seconds. One with a single dollar figure gets sent back with questions. Our detention invoice template lays it out line by line.