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Demurrage and detention calculator

Demurrage is charged for each day a full container stays in the port after its free time ends; detention is charged for each day the container is kept outside the terminal before the empty is returned. Enter your free days, the carrier's tiered daily rates and the dates to estimate the last free day and the likely charge.

A full container waiting inside the port or terminal.

Use an expected date to estimate future charges.

As stated on your booking or in the carrier's tariff.

Most carriers count the discharge or gate-out day as the first free day. Check your tariff.

Daily rates after free time

Carriers usually charge in tiers, for example days 1–5, then days 6–10, then a higher rate. Enter how many days each tier lasts and its rate per container per day. The last tier has no end.

  1. Days 1–5

  2. Days 6–10

  3. Day 11 onward

Estimate

Enter the start and end dates to see the chargeable days and the estimated cost.

Estimate only. Actual charges follow the carrier's or terminal's tariff, which may count days differently, include or exclude weekends and holidays, add VAT or bill port storage separately. Rates change often, so ask us for the current tariff for your line and port.

Ask us to check your free time

What is the difference between demurrage and detention?

Demurrage is charged by the shipping line for every day a full container stays inside the port after its free time. The terminal may also charge port storage for the same period. Detention is charged for every day you keep the container outside the terminal, from gate-out until the empty is returned to the depot. Some lines combine both into one merged demurrage and detention free-time period.

How is the charge calculated?

  1. Find when free time starts: usually the discharge day for import demurrage, or the gate-out day for detention.
  2. Add the free days to find the last free day.
  3. Count the days after that until the full container leaves the port (demurrage) or the empty is returned (detention).
  4. Multiply each day by the rate of its tier, then by the number of containers.

Worked example: 7 free days, then USD 20 a day for days 1–5, USD 40 a day for days 6–10 and USD 80 a day after that. A 40′ discharged on 1 March and gated out on 15 March has spent 15 days in port, counting the discharge day. The last free day is 7 March, so 8 days are chargeable: 5 × 20 + 3 × 40 = USD 220 per container. These rates are an illustration, not a tariff.

How can you avoid demurrage and detention?

  • Prepare the documents before the vessel arrives: the original bill of lading or telex release, invoice, packing list and any certificates.
  • Pay freight and duties in time for the delivery order to be issued.
  • Ask for extra free days at booking. Lines often grant them for a fee or for regular volumes, and they cost far less than demurrage later.
  • Plan unloading at your warehouse so the empty goes back within the detention free time.
  • Check weekends and public holidays at the destination port.

In the Nil Ocean customer portal, each container shows the agreed free days so you can act before charges start.

Why is this only an estimate?

Every carrier and terminal publishes its own tariff. Tariffs differ on whether the first day counts, whether weekends and public holidays count, whether free time is in calendar or working days, and whether port storage is billed separately from the line's demurrage. VAT may also apply. Use this tool to understand the order of magnitude, then check the tariff that applies to your bill of lading.

Frequently asked questions

When does free time start?

For import demurrage it usually starts on the day the container is discharged from the vessel; for detention it starts when the container leaves the terminal. Your carrier's tariff or booking confirmation states the exact rule.

Is demurrage charged at weekends and on public holidays?

Usually yes: most carriers count calendar days, including weekends and public holidays. Some tariffs exclude them, so check the terms for your line and port.

Can free time be extended?

Often, if you ask at booking. Shipping lines sell or grant extra free days, which is far cheaper than paying demurrage later. Ask us to include the free days you need in your quote.

Who pays demurrage, the shipper or the consignee?

It depends on the sales contract and Incoterm. At destination, the party collecting the cargo, usually the consignee, pays the line before the delivery order is released. Costs caused by the other party's delay can then be recovered under the sales contract.

Next step

Worried about free time on a shipment?

Tell us the line, the port and the dates. We will check the tariff and the options to extend free time before charges start.

Get a quote
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  • Itemised quote, no changes without your approval
  • Replies in English, Arabic or Persian