Demurrage & Detention Calculator
Estimate demurrage (vessel/container held at terminal) and detention (equipment held outside terminal) after free-time expiry. Supports tiered carrier rates for boxes or fixed daily hire/laytime penalties for bulk and tanker vessels.
Default detention tiers: d1–5: 90 · d6–10: 180 · d11+: 300
Numerical Example: Container D&D Estimate
Calculation based on standard carrier tiered rates for container equipment.
| Type | Tier | Days | Rate | Cost |
|---|---|---|---|---|
| Demurrage | Day 1–4 | 3 | $75.00 | $225.00 |
Overview & methodology
Who pays demurrage and detention, and when the clock starts
| Charge | Where the container is | Who is liable | When the clock starts |
|---|---|---|---|
| Import demurrage | Full, inside the discharge terminal | Consignee / B/L holder | When the container is discharged and available, until full gate-out |
| Import detention | Outside the terminal, at the consignee or in transit | Consignee / B/L holder | At full gate-out, until the empty container is returned to the depot |
| Export detention | Empty picked up, at the shipper's premises | Shipper | At empty gate-out from the depot, until full gate-in at the load terminal |
| Export demurrage | Full, inside the load terminal awaiting the vessel | Shipper | At full gate-in once export free days end, until loaded on board |
Free time pooling
Some carriers grant separate free days for demurrage and for detention. Others grant one combined pool that covers both and is used up day by day from discharge until empty return, so every extra day inside the terminal reduces the days left before detention starts. The carrier bills the merchant named on the bill of lading; who finally bears the cost between buyer and seller depends on the sales contract and Incoterm. Use the Combined mode above to model a pooled tariff.
Demurrage vs detention
Demurrage is the charge for keeping a full container inside the terminal beyond free-time. Detention is the charge for keeping the container (or the chassis) outside the terminal - after unloading - beyond the return free-time. Carriers either give separate free-time pools (carrier haulage) or a single combined pool (merchant haulage) that is consumed chronologically.
Method note: calculations run in your browser using the formulas and published rule books cited on this page. Results are free estimates for planning, with no login required, and should be confirmed with your bank, broker or the official source before you commit.
Frequently asked questions
What is the difference between demurrage and detention?
Demurrage is charged while a full container stays inside the terminal after free time ends. Detention is charged while the carrier's container is outside the terminal, from gate-out until the empty box is returned. The handover point is the terminal gate.
When does the demurrage clock start?
For imports it normally starts when the container is discharged and available at the terminal, and free days are counted from that point. The exact start, free days and daily rates are set in each carrier's tariff, so check the tariff that applies to your bill of lading.
What is pooled or combined free time?
Some carriers give one combined pool of free days covering both demurrage and detention. The pool is used up day by day from discharge until empty return, so days spent inside the terminal reduce the days left before detention starts.
Are demurrage rates tiered?
Yes, almost always. A common structure is Tier 1 (days 1–3 past free-time) at USD 100/day, Tier 2 (days 4–7) at USD 200/day, Tier 3 (days 8+) at USD 400/day. Free-time and tier rates vary by carrier, port and container size.