Container Detention Fee Calculator

Detention charges you for keeping the carrier's or leasing company's container itself past the agreed free time, wherever it physically is — at your warehouse, a rail yard, or still at the port. Demurrage, by contrast, charges you specifically for leaving cargo sitting at the port terminal too long before pickup. This calculator only models detention: the per diem cost of holding the equipment.

The calculator applies your Tier 1 rate to the first block of chargeable days (Tier 1 Duration, 6 by default) and then switches to the steeper Tier 2 rate for every chargeable day beyond that block. This mirrors how carriers actually structure detention tariffs — a modest per diem at first that escalates the longer the container sits, since the goal is to pressure fast returns rather than to profit from long holds.

Chargeable days is Total Days Held minus Free Time (days), floored at zero — so if you return the container within the free-time window, chargeable days is 0 and no detention accrues at all. It's this chargeable-days figure, not the total days held, that gets split across the Tier 1 and Tier 2 rate blocks.

Often, yes. If port congestion, customs holds, or a carrier-caused delay pushed your total days held past free time, most carriers will consider a detention waiver or credit for circumstances outside your control — but you generally need to request it, and do so before or shortly after the charge posts rather than after paying it. This calculator shows what you'd owe under the stated terms; it doesn't know whether a waiver applies to your situation.

Yes — the calculator first works out the detention cost for a single container (Tier 1 Cost plus Tier 2 Cost) and then multiplies that per-container figure by Number of Containers to get Total Detention. The Avg Daily Rate output, however, stays per-container: it divides the per-container cost by chargeable days, so it doesn't change just because you're tracking more boxes.