What is that box actually costing you? Enter the dates and your tariff — the calculator shows the days over, the tier breakdown, and the bill as it stands today.
Demurrage starts when your free time runs out. The clock begins at container discharge from the vessel (not vessel arrival — a common billing error), free days count from there, and each day beyond them is billed at your tariff's tier for that day. Tiers escalate: a typical shape is one rate for the first few days over, roughly double for the next band, and more again beyond that. Detention works the same way outside the terminal, from gate-out until the empty is returned.
The number this tool shows is also the number worth auditing: 20–30% of disputed demurrage & detention charges are overturned when checked against the contract and the terminal's own timestamps. Marevo does that automatically — here's the full dispute process, and the retro-audit of your last quarter is free.