Demurrage & Detention Cost Calculator
The Demurrage & Detention Cost Calculator computes container charges from free days, actual days held, and daily rates: chargeable days are the days beyond free time, multiplied by the carrier's daily rate — with support for tiered rates that escalate after the first days and totals across multiple containers.
Input Parameters
Days the container sat in the port/terminal beyond free time.
Results
Enter values to see results
Formula
Chargeable Days = max(0, Days Held − Free Days) · Cost = (Tier-1 Days × Tier-1 Rate) + (Tier-2 Days × Tier-2 Rate)Demurrage applies while a container sits inside the port or terminal beyond its free time; detention applies to the equipment kept outside the port beyond free time (for example, at your warehouse before the empty is returned). Carriers commonly tier the rates: a lower rate for the first chargeable days (tier 1, days 1–5 here) and a higher rate thereafter. Charges accrue per container per calendar day.
Variable Definitions
Number of Containers
How many containers the charge applies to on this shipment.
Free Time
Days included before charges start, per your carrier contract or tariff — commonly 3–7 days.
Actual Days
Total days the container was in the port (demurrage) or out with the equipment (detention).
Daily Rates
Cost per container per day. Tier 1 covers chargeable days 1–5; tier 2 applies from day 6 onward.
Example Calculation
Scenario: An importer's 4 containers cleared customs late: - Free time: 5 days; containers picked up on day 12 (7 chargeable days each) - Demurrage rate: $150/day for days 1–5, $300/day from day 6 Calculation (per container): Chargeable days = 12 − 5 = 7 Tier 1: 5 days × $150 = $750 Tier 2: 2 days × $300 = $600 Cost per container = $1,350 Total for 4 containers = $5,400 — most of it avoidable with faster customs pre-clearance and drayage booking before vessel arrival.
How to Interpret Your Result
• Demurrage and detention are pure waste — they buy nothing. Track them as a KPI and target zero. • The tiered structure means the last days are the expensive ones: cutting 2 days off a 7-day overage often saves more than cutting the first 2 days. • Root causes are usually process, not port: late customs documents, slow drayage booking, chassis shortages, or weekend receiving gaps at your DC. • If charges recur on a lane, compare the annual total against the cost of more free days negotiated into the next carrier contract.