Demurrage Calculator

Count the days the container spends at the terminal, using your tariff's start date, and subtract the free time. What's left are the chargeable days, meaning the days charged after free time ends. Fill the rate tiers in order: the first-period days at the first rate, the second-period days at the second rate, and every remaining day at the thereafter rate. Multiply each tier's days by its daily rate and add them up to get the charge per container, then multiply by the number of containers. Before you enter the tiers, check how your tariff writes them. Some count from the first chargeable day, while others count from the start of the clock with free time included, so those need converting to chargeable days first.

The difference comes down to where the container is. Demurrage applies while the loaded container sits inside the terminal beyond its free time. Container detention covers the time it spends outside the terminal. On an import, detention starts when the full container is picked up and ends when the empty is returned to the container yard (CY). The FMC describes detention as a charge for extended use of intermodal equipment. In US trucking, "detention" also means a driver's waiting-time fee, which is a separate charge.

There's no standard number. Free time comes from the carrier's tariff or your service contract (a negotiated contract with an ocean carrier), and it varies by port, carrier, equipment and facility. Some examples: Hapag-Lloyd's German import tariff, in force since January 1, 2026, gives standard dry containers 4 calendar days at Hamburg and Bremerhaven and 7 at Wilhelmshaven. Maersk's combined demurrage and detention tariff for Seychelles imports allows 10 days for dry containers, 3 for reefers and 5 for special equipment. Hapag-Lloyd's US import tariff that ran from October 1, 2023, to June 14, 2024 (no longer current) allowed the discharge day plus 4 working days (days the terminal or facility is open). Special equipment often gets less: that same US tariff allowed the discharge day plus 3 working days for special equipment and tank containers, and plus 2 for operating reefers. Check whether your free time is counted in calendar days (every day, weekends included) or working days.

On imports, the carrier decides. The clock can start at vessel arrival, during discharge or once discharge is complete. Discharge usually takes 2–3 days and can take up to a week in exceptional cases, so the start rule can make a big difference to the bill. Tariffs also disagree on what counts as Day 1: Hapag-Lloyd's German tariff starts on the day the container is discharged, while other carriers start the day after gate-in at the container yard, and weekends and holidays aren't always counted the same way. On exports, demurrage runs from gate-in at the terminal until the container is loaded or the vessel sails. The calculator treats the start date you enter as Day 1 and includes the end date.

There's no single market rate. Demurrage is billed per container and per day, and the rate depends on the location, the equipment type and the tier you're in. Under Hapag-Lloyd's German import tariff at Hamburg and Bremerhaven, a 20ft container costs €80 a day for the first 4 chargeable days, €120 for the next 5 and €190 a day after that (€120, €190 and €240 for a 40ft). Hapag-Lloyd's expired 2023–2024 US import tariff charged $200, $250 and $300 per working day for standard containers. Use the rates from your own tariff or quote. The calculator shows a $ sign, but the arithmetic works the same in whatever currency you enter.

Demurrage compensates the owner of the equipment or facility, and it gives the cargo owner a reason to return the container or free up the space. Carriers also use it to stop containers being stored at the port for long periods. Because the daily rate rises with each tier, the average cost per day rises the longer the container stays. In the example on this page, the first chargeable day costs $150, but the average over five chargeable days is $210.

In the US, 46 CFR Part 541 has applied since May 28, 2024, under the Ocean Shipping Reform Act of 2022. It covers demurrage and detention invoices issued by ocean carriers, marine terminal operators and NVOCCs (non-vessel operating common carriers). To identify the shipment, the invoice must give the bill of lading number, the container number, the port of discharge for imports, and the basis for why the billed party is the proper party and liable for the charge. For timing, it must show the invoice date, the due date, the free time allowed, the dates free time started and ended, the container availability date for imports (the date the container became available for pickup), the earliest return date for exports, and the dates charged. For the rate, it must state the total amount, the tariff or service contract provision the charge is based on, and the rate applied. It also needs a contact for questions, instructions and deadlines for requesting mitigation, a refund or a waiver, and a certification that the charges comply with FMC rules and that the billing party's own performance didn't cause them. If required information is missing, you have no obligation to pay. The invoice also has to be issued within 30 calendar days of the last day charges accrued, or payment isn't required, and you get at least 30 calendar days from the invoice date to request mitigation, a refund or a waiver.

Have the cargo ready on time and start customs clearance before the vessel arrives. A freight forwarder can help you negotiate longer free time or better rates. Make sure your quote spells out the demurrage and detention rates and the free time, per container and per day, and keep the trucker, broker and consignee informed so pickup isn't delayed. Some carriers, Maersk among them, let you buy extra detention days when you book an import. If the container is gated out within free time, you pay no demurrage for that period, though detention and storage charges are billed separately.

It depends on the terms of your contract and bill of lading, so check those first. At some terminals, the terminal operator bills its own demurrage and storage directly instead of the shipping line. For US invoices under FMC rules, the invoice has to state why the billed party is the proper party and liable for the charge. If that's missing, there's no obligation to pay. A separate FMC provision that limited who could be billed (§541.4) was set aside by the D.C. Circuit on September 23, 2025, and removed from the CFR on December 29, 2025.

They overlap. Per diem is a daily charge for using the carrier's equipment outside the terminal, which is essentially what container detention covers. FMC rules count per diem as part of demurrage and detention charges. Check how the carrier's tariff defines whichever term appears on your invoice.

Yes. In most South American countries the terms are inverted: demurrage refers to time outside the port and detention to time inside it. If you trade with South America, agree with your counterparts which term means what before you compare quotes or dispute an invoice.

Only as a rough check. The calculator counts calendar days, with the start date as Day 1 and the end date included, and it can't skip weekends or public holidays. If your free time or tiers are set in working days, count the chargeable working days yourself using your tariff's rules. The calculator also takes just two tiers plus a thereafter rate, so a tariff with more steps won't be reproduced exactly.