Container Demurrage & Detention Calculator

Demurrage and detention are the two container delay charges that most often surprise importers. Both are charged by the shipping line when its containers are used longer than the free time granted, but they apply in different places. Demurrage runs while the full container stays inside the terminal or port depot after discharge, until it leaves through the gate. Detention runs once the container has been taken out of the terminal to your warehouse, until the empty is returned to the nominated depot. For exports the pattern is reversed: detention from empty pick-up, demurrage from gate-in of the full box until loading.

Some lines give separate free time for each (e.g. 4 days demurrage and 7 days detention), others a combined or merged free time (e.g. 14 days from discharge until the empty is back). After free time, daily rates are usually tiered: the first days are cheaper, then the rate steps up. Rates also differ for 20', 40', reefer and special equipment. On top of the line's charges, the terminal may bill its own storage.

This calculator counts the chargeable days from dates (discharge, gate-out, empty return) or straight from a number of days, then spreads them over rate tiers you can edit, for one container and for the whole shipment. Counting rules differ by carrier (whether the discharge day counts, calendar or working days), so match them to your tariff or contract.