Demurrage & Detention Calculator
Calculate exactly what you owe - and understand how to avoid it next time
Number of containers
Demurrage
Container sitting at port / terminal
Free days included - charges start day 6
Detention
Carrier equipment off-port
Free days included - charges start day 6
Enter actual days above to calculate charges
Demurrage, Detention & Storage - what is the difference?
These three charges are often confused. Each starts at a different point in the container journey and is billed by a different party.
Container sits at the terminal
Demurrage is charged by the port terminal (or passed through by the carrier) when an import container is not picked up within the free time period. The clock starts the moment the container is discharged from the vessel and stops when it exits the terminal gate. Typical free time: 3–7 days.
Charged by
Terminal / Carrier
Clock starts
Vessel discharge
Clock stops
Container exits terminal gate
The key distinction: demurrage = container at port. Detention = carrier box off-port. Storage = cargo at CFS.
Where demurrage and detention clocks start and stop
Understanding the exact moment each clock starts is essential to avoiding unexpected charges.
Vessel arrives
Ship berths at port - container waiting to be discharged
Container discharged - demurrage free time begins
Typically 3–7 free days depending on carrier and trade lane
Free time expires - demurrage clock running
Every calendar day beyond free time is charged at the carrier's daily rate
Container picked up at gate
Demurrage clock stops. Detention free time begins immediately.
Detention free time running
Carrier's container is with you - typically 3–7 free days
Detention free time expires - detention charges accumulate
Every day the empty container is not returned costs money
Empty returned to depot
All clocks stop - final charges calculated and invoiced
Why shippers get hit with unexpected charges
Most demurrage and detention bills are avoidable. These are the six most common reasons shippers get caught out.
Not knowing your free time allowance
Free time is not standard - it varies by carrier, port, trade lane, and whether you have a service contract. Always confirm in writing before the vessel arrives. Some carriers offer 14 free days; others just 3.
Customs holds eating free time
Customs inspections, missing documents, or failed examinations freeze your shipment while the demurrage clock keeps running. Pre-clear all documentation and use a licensed customs broker for every import.
Late import documentation
If the original Bill of Lading or telex release is not received before the vessel arrives, you cannot pick up the container. Every day waiting for documents is a chargeable demurrage day. Chase documents at least 5 days before ETA.
Slow empty container return
Once cargo is delivered, the empty must be returned promptly. A container sitting on a truck or in a yard accumulates detention charges daily - even if your cargo was delivered on time.
Not tracking containers individually
If you have 10 containers on one shipment, they may discharge 1–2 days apart due to vessel stowage sequence. Each container has its own separate free time clock. Missing one can cost hundreds of dollars.
Assuming weekends do not count
Most carriers and terminals count calendar days - not working days - for demurrage and detention. Always check the carrier's tariff. Only some carriers offer working-day free time, and usually only for detention.