The day your container is unloaded from the ship, two or three separate clocks start running, and nobody sends you a warning when they do. Each one belongs to a different company, each one has its own free period, and each one gets more expensive the longer it runs. On most shipments that go wrong, the loss is not the customs duty. It is the days.
Pick your terminal and your shipping line and this tool loads their published rates for you. Then it shows what the delay is costing, what one more day costs, and the date your rate jumps. Not on the list? Type your own figures, for any port in the world. Nothing you type leaves your device.
First, the three clocks (most people only know about one)
These three words get used as if they mean the same thing. They do not. They are charged by different companies, for different reasons, over different periods. Knowing which one is running is how you know who to call.
Demurrage
Charged by: the shipping line
Rent on their container while it is still sitting inside the port. The line wants its box back in circulation. Every day it sits full in the terminal, they charge you.
Runs from: the day the ship is unloaded Stops: the day you take the container out of the port
Storage (also called ground rent)
Charged by: the terminal
Rent on the ground your container is standing on. Completely separate from the line's charge, and it usually rises in steps that get steep fast.
Runs from: the day the ship is unloaded Stops: the day the container leaves the gate
Detention
Charged by: the shipping line
Still rent on their container, but now for the period after you have taken it out. It runs while the box is at your warehouse being emptied, and it does not stop until you hand the empty back.
Runs from: the day you take the container out Stops: the day you return the empty container
Watch out Some carriers merge demurrage and detention into one clock with one free period, often called combined free time or merged demurrage and detention. Others keep them separate, which means two free periods and two bills. Your bill of lading or your booking confirmation says which, and where a line on the list below publishes a combined tariff this tool switches to it for you.
Step 1: where is it, and whose box is it?
Pick these and the published rates load themselves. You can change every figure afterwards.
Step 2: your dates
Tap the ? beside any field for a plain-English explanation.
Step 3: the free days and the rates
Read this first
Where these numbers come from. When you pick an operator above, the figures are taken from that company's own published tariff, and the note under Step 1 tells you which document and when it was last checked. Where nothing is picked, the boxes hold example figures, not real rates.
Free days are the part that varies most. A carrier publishes a standard tariff, but free time is contractual. A shipper with volume or a service contract may hold 14 or 21 free days on a lane where a one-off importer gets 5 or 7. If you booked through a freight forwarder, the free days are whatever they negotiated. So always check your own booking confirmation and change the free days here to match it.
Rates rise in bands. The first few chargeable days are cheap, the next few cost more, and after that it gets punishing. That is deliberate: the charge exists to make you move the box, not to earn rent.
Band days here are counted after the free days run out. So "days 1 to 3" means the first three chargeable days, not the first three days in the port. Leave the second box of the last band empty and it means and onwards, with no end.
Demurrage shipping line, inside the port
Storage terminal, ground rent
Detention shipping line, after the gate
Step 4: the clock
This is an estimate, not an invoice. The loaded rates are taken from published tariffs on the dates shown and operators revise them, sometimes at short notice. Carriers and terminals also apply their own rounding rules, holiday calendars, container-type differences and occasional waivers, and some ports charge extra items this tool does not model, such as power for refrigerated containers or special handling. Always check the final figure against the bill you are actually given, and against your own booking.
Tap a heading to read it.
Why these charges exist at all
It is tempting to read a demurrage bill as a punishment. It is not. A shipping line owns a finite number of containers, and every one standing full in a port is a box that cannot be earning money on another voyage. A terminal has a finite amount of ground, and every slot occupied by your container is a slot the next ship cannot use. The charge is the price of holding something that other people are queuing for.
That is why the rate climbs in steps. A flat charge would simply be rent, and some importers would happily pay rent to use a port as a warehouse. A rising charge makes that unaffordable on purpose. Once you see it that way, the tool changes: you stop asking "can I get this waived" and start asking "what is the cheapest day for me to move this box".
The single most useful number on this page
It is not the total. It is the cost of one more day. That number tells you instantly whether it is worth paying extra for a faster truck, an overtime examination, or a same-day bank transfer. If one more day costs more than the fix, buy the fix. People lose money here not because they cannot do the arithmetic but because nobody ever put the two numbers side by side.
Can they actually charge you this?
Usually yes. Ordinary demurrage, detention and storage sit in the carrier's published tariff and the terminal's published tariff, and your bill of lading points at them. That makes them payable even when they feel unfair.
But not every charge that lands on an invoice is one of those, and an unusual one is worth questioning before you pay it. In Nigeria the regulator recently ruled that a very large daily detention charge could not be enforced against the importers at all, because the clause creating it lived in a contract between the vessel charterer and the line. The importers were not party to that contract, and their own bill of lading said nothing about it.
The lesson is narrow but useful: check that the charge you are being billed actually appears in your own bill of lading or in the operator's published tariff. If it does not, ask in writing where it comes from before you pay.
Seven ways people actually cut this bill
One: start the paperwork before the ship sails, not when it lands. Almost every long delay traces back to a document that could have been obtained weeks earlier. The clock does not care why you are waiting.
Two: ask for the free days in writing at booking. Free days are negotiable, especially on regular volume or on a difficult inland destination. Nobody offers them to a customer who never asks.
Three: know both tariffs before the box arrives. If you cannot say what day seven costs and what day fifteen costs, you cannot plan around either. That is what the list in Step 1 is for.
Four: watch the band dates, not the total. Collecting one day earlier can be worth far more than it looks if that day is the last one before a band changes. The tool shows you those dates.
Five: return the empty on time. Detention keeps running after the container reaches your yard, and this is the clock people forget completely because the goods have already arrived and everyone has moved on.
Six: front the money where the delay is a payment. Waiting on an internal approval while a container accrues charges is one of the most expensive habits in the business, and it is entirely self-inflicted.
Seven: keep the evidence. Where a delay was genuinely caused by the port, the carrier or a regulator, a written record of dates makes a waiver request possible. Without dates you have an opinion, not a case.
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