A truck can spend hours at a shipper or receiver while the carrier still has to pay its driver, finance equipment and manage an increasingly difficult appointment schedule. A detention charge may help offset that loss. But an accessorial charge on a spreadsheet is not the same as a right to payment, and a right claimed on an invoice is not cash in the bank.
A useful calculation must answer three different questions. How much would the agreed rate produce? How much has the customer actually paid? How much did the wait cost the carrier? Each number informs a different decision about the next load, the broker relationship and the carrier’s working capital.
Use the free Detention & Layover Revenue Calculator to enter your actual terms. This guide works through the formulas and explains the evidence needed before asking for payment. For the wider procedures for protecting accessorial compensation, see our existing detention, layover and TONU documentation guide.
Detention is not just hours on the dock
First distinguish dwell time from chargeable detention. Dwell is the full interval at a facility. Detention is the portion of that interval that meets a defined compensation trigger in the agreement. Those figures can differ by hours even when everyone agrees on the timestamps.
A rate confirmation might allow two free hours after an appointment, require a check-in or on-time arrival, and pay a negotiated rate for approved additional time. Another contract may allow a different free period, start the clock after a specified loading window, demand an approval email, or exclude delays caused by the driver’s own paperwork or lateness. Those differences belong in the calculation before anyone multiplies time by a rate.
This is why the tool asks for agreed free time as a user input. Do not interpret its two-hour sample as a statutory entitlement. The Federal Motor Carrier Safety Administration’s detention research studies the operational and safety problem; it does not establish a single nationwide schedule of mandatory detention fees.
Confirm what starts and stops the clock
Record the scheduled appointment time, the moment the vehicle arrived, gate check-in, dock-in time, completion of loading or unloading, and the actual release time. Your contract might use some of these events rather than others.
Suppose the truck is scheduled for 9:00 a.m., checks in at 8:50 a.m., receives a door assignment at 11:15 a.m. and is released at 3:20 p.m. Different contract clock definitions could produce different detention totals. Calculating from check-in is one possible scenario, not necessarily the correct invoice. Before submitting a fee, reconcile the start and stop timestamps with the rate confirmation.
The detention formula
For a simple agreement where detention begins once the grace period expires:
Chargeable hours = maximum of zero and (eligible facility time minus free hours).
Then apply the billing rule. If the contract bills in 30-minute increments and rounds upward, 4.1 chargeable hours become 4.5 billed hours. If it bills in 15-minute increments, 4.1 hours become 4.25 billed hours. If the agreement permits only complete 60-minute increments and rounds upward, 4.1 hours become 5 billed hours. Never quietly substitute one method for another.
Requested detention charge = billed hours multiplied by the hourly rate, subject to any separately stated detention cap. A cap on detention should not automatically reduce an authorized layover charge unless the agreement applies one shared overall cap.
Our calculator provides quarter-hour, half-hour and whole-hour increments and an optional detention cap. Enter zero for the cap when no cap is specified. It is intentionally conservative about the scope of the calculation: the software does not decide whether the broker will accept the documentation.
Worked example: 6.5 hours at a receiver
Consider the following fictional shipment. The carrier documents 6.5 hours of eligible dwell time. The written contract permits 2 free hours, bills in half-hour increments and pays $75 for each billed detention hour.
| Calculation component | Amount |
|---|---|
| Recorded facility dwell | 6.5 hours |
| Agreed free time | 2 hours |
| Chargeable wait | 4.5 hours |
| Billed wait | 4.5 hours |
| Agreed rate | $75 per hour |
| Detention requested | $337.50 |
Here the excess is already a multiple of 30 minutes, so no additional rounding occurs. With a different recorded wait, the increment can matter. A 4.1-hour excess would produce a 4.5-hour bill under half-hour upward rounding, even though the actual excess time was lower.
Now suppose a separate, properly authorized overnight layover qualifies for a $200 fee. Under the example contract, the requested accessorial total becomes $537.50: $337.50 detention plus $200 layover. The overnight fee is not inferred from the clock. It exists only because the appropriate event and commercial authorization occurred.
If the carrier has received only $300 toward those accessorial charges, $237.50 remains uncollected. This difference is not proof that the broker is legally overdue or that payment will arrive; it is a reconciliation between the requested amount and the cash recorded in this scenario.
Add the opportunity cost of waiting
A detention payment can help but may not fully compensate for lost productive capacity. Suppose the carrier estimates its direct operating or opportunity cost of wait time at $43 per hour for the 6.5-hour interval. The model estimates $279.50 in waiting cost.
At the $300 actually collected, the contribution after that narrowly defined cost is $20.50. At full payment of $537.50, it would be $258.00. Both figures exclude many possible costs and revenues. They are not overall load profit and should not be presented as such.
The $43-per-hour example is an assumption, not an industry average or officially approved rate. In practice, a carrier’s opportunity cost might depend on driver pay arrangements, missed utilization, whether driving hours are affected, idle fuel, parking and the next load’s availability. Do not multiply a fully allocated truck expense and then add the same component again under a different label.
If you already calculate full-trip profitability, use the Load Profitability Calculator to analyze the trip separately, making sure accessorial revenues and expenses are not counted twice.
Layover: a different trigger from waiting during the day
Layover commonly describes a disruption that extends into an overnight or additional operating period under agreed commercial terms. However, the event definition, fee, approval method and whether layover replaces or supplements detention vary by contract.
A rate confirmation might provide a daily or nightly layover amount, require broker approval before an overnight stay, or state that detention does not accrue during periods covered by layover. In those cases, combining both fees for the same hours could create an unsupported invoice.
Our calculator treats layover as billable nights multiplied by the entered per-night rate, and it relies on the user to enter only nights genuinely allowed under the contract. It does not automatically create a layover fee because a truck waits six hours, misses a second load or happens to be at a site after midnight.
For a one-night agreed amount of $200, the modeled layover is $200. For two independently qualifying nights it would be $400. If a per-event cap, approval requirement or exclusion overrides that simple arithmetic, reconcile those terms outside the calculator before invoicing.
Truck ordered not used: cancellation is not ordinary detention
A load cancelled after the carrier has committed equipment can create a different loss. Under an appropriate written agreement, a truck ordered not used (TONU) fee may be payable when a truck is dispatched or positioned and the shipment is cancelled or unavailable.
Do not assume every cancellation qualifies. Your commercial terms may require the carrier to reach a particular point, prove the truck was ready, notify the broker quickly, or accept a negotiated flat fee. Determine the triggering event before discussing the amount.
The tool has a separate TONU event selector. In that scenario, it uses the contracted cancellation amount and does not add ordinary completed-load detention and layover fees. If a real agreement explicitly allows additional documented charges, prepare those as separate supported line items rather than assuming that overlapping fees automatically belong together.
A cancellation example
Suppose a rate confirmation specifies a $250 TONU payment for a qualifying late cancellation. The carrier has documentation showing it met the conditions but has received $100 so far. The scenario shows $250 requested and $150 uncollected. It does not show an extra $75 per hour merely because the vehicle had been staged near the pickup, nor does it charge the original linehaul as if the completed shipment occurred.
The carrier may have additional economic losses, but they are not automatically identical to compensable contract charges. Recording those losses in an internal dispatch analysis can help negotiate future terms without confusing the invoice.
Why the difference between requested and collected matters
Many carriers understand the formula yet have difficulty converting the result into a payment. The American Transportation Research Institute detention study described by the Transportation Research Board reports that detention fees were often billed but not always paid in the study population. That is a research finding, not a forecast for any individual broker or a substitute for reviewing the carrier’s contract.
The operational lesson is to track accessorial claims using at least four stages: documented event, fee requested, fee approved or disputed, and payment collected. A claim awaiting approval is not cash. An invoice sent yesterday is not the same as an accepted claim. Partial payment requires its own record and may need a specific follow-up.
In our tool, requested and collected amounts remain separate. The uncollected amount is simply the difference. That figure can be exported in CSV with your input assumptions, giving the carrier a starting point for reconciliation rather than a fabricated automatic receivable.
Consider also how collection timing interacts with cash flow. If drivers and equipment must be paid this week while accessorial invoices are settled next month, a good theoretical profit figure can still accompany an immediate cash shortfall. Our Carrier Cash Runway Calculator helps explore that gap with your actual invoicing assumptions.
The evidence package before submitting a claim
An effective detention claim begins before the truck reaches the gate. Read the rate confirmation for free time, eligibility, notice deadlines, documentation requirements and billing increments. Then establish a repeatable method for collecting time records from dispatch, the driver and the facility.
When the truck arrives, document the scheduled appointment and actual arrival. Keep check-in confirmation, door assignment records where available, driver communications and any electronic timestamps. At release, record departure and obtain the appropriate BOL, POD or in/out stamp where the agreement expects one.
If the facility refuses to sign arrival or departure times, preserve the contemporaneous communications and any permitted supporting records, and contact the broker promptly rather than manufacturing a signature. Use ELD or tracking records carefully: they may corroborate a truck’s location and status, but they are not always conclusive proof of which time counts under the contract.
If a hold appears likely to exceed the free period, notify the broker in the manner and within the timeframe agreed. Where written approval is required for detention, layover or cancellation fees, secure and preserve it. A verbal conversation with a warehouse attendant might not satisfy a requirement for broker authorization.
Finally, reconcile the fee against the actual rate confirmation and provide a readable calculation. A short table stating timestamps, free time, contracted billing increments, eligible hours, hourly rate and requested total is easier to verify than an unsupported lump-sum amount.
How to use the calculator without overstating revenue
Start with the completed load event for detention or layover. Enter facility time and contractual free time, choose the agreed billing increment and rate, and enter a detention cap only if one applies. Add layover nights only where separate written terms actually allow a layover claim.
The tool then produces chargeable and billed hours, detention, layover and the overall requested amount. Record only fees actually paid in the collected field. To model the effect of the wait on operations, supply a reasoned hourly waiting cost—or set it to zero when you do not have support for an estimate.
For a qualifying cancellation instead, choose the TONU event. The screen hides completed-load fee fields and uses only the cancellation charge. It resets the collected-value input to zero when switching event types to avoid silently carrying over an unrelated payment from the earlier example. Enter any actual collection for the cancellation after switching.
The downloadable CSV records assumptions and calculated results; it is not an invoice, rate confirmation or claim acceptance. The contract, the approval workflow and the evidence still control whether and how any charge should be pursued.
Common mistakes that distort the result
An obvious mistake is charging from the scheduled appointment without checking what the contract says when the driver arrives late. Another is using the published hourly amount but skipping a contractual cap or minimum billable increment. The mathematics can be correct while the invoice is still inconsistent with the commercial agreement.
It is also easy to double count overlapping time. A long wait may cross midnight, but that does not automatically entitle the carrier to both an entire night of layover and detention over the same hours. Likewise, cancelling a load does not mean its full linehaul is necessarily earned plus TONU and detention.
A third mistake is treating requested revenue as collected cash in the truck’s profit model. Use the actually collected figure for realized cash analysis, and manage approved but unpaid claims separately. If you are projecting future weeks, distinguish expected collections from invoices that have already cleared.
Finally, do not ignore the carrier’s operating economics. A $300 payment may be meaningful for a short disruption and inadequate for one that destroys the next day’s scheduled dispatch. The economic loss and the compensable contractual charge remain different concepts.
How to improve future rate confirmations
After a series of shipments, review where delays occurred, which customers accepted accessorial charges, how long payment took and how documentation was handled. That history can inform future negotiations: a clearer clock trigger, less ambiguous notification requirements, a rate aligned with actual opportunity cost, or a defined approval process for layovers and cancellations.
Review the rate confirmation checklist before dispatch. If your operation routinely serves a shipper with unpredictable dock times, the quality of the contract may matter as much as the headline linehaul rate.
The U.S. DOT Office of Inspector General’s detention findings emphasize that waiting has significant effects on operations and safety at an industry level. For an individual carrier, the practical response is to document delays, follow agreed procedures and analyze cash actually recovered—without presenting research estimates as an enforceable fee schedule.
Bottom line
There is no dependable detention revenue forecast without three pieces of information: the event timestamps, the actual commercial agreement and the collection status. Use the formula to build a claim, preserve support for every required condition, and keep a separate view of the carrier’s delay cost.
Open the Detention & Layover Revenue Calculator and replace the editable example values with the terms on your own rate confirmation. Then use the results alongside a documented claim package rather than treating the calculator itself as proof that payment is owed.