Laytime calculation: a worked VLCC demurrage example
How tanker laytime and demurrage are actually calculated — NOR, laytime commencement, exclusions, and a complete worked example of a $190,000 VLCC claim, step by step.
The pieces
The charter party (CP) grants the charterer an allowance of laytime — commonly 72 hours total for loading plus discharge in crude trades — and sets a demurrage rate per day, pro rata (PDPR). The master tenders Notice of Readiness (NOR) on arrival; after any contractual turn time, laytime starts counting. Every port event is recorded in the Statement of Facts (SOF). When laytime is used up, the vessel is 'on demurrage' and every further hour is owed at the CP rate.
Exclusions are where the arguments live: many CPs stop the clock for weather interruptions, shifting between berths, or time before NOR was validly tendered. The SOF's timestamps decide each one.
Worked example
Fixture: a VLCC loading 2.0M barrels at Ras Tanura for discharge at Ningbo. CP terms: 84 hours total laytime; demurrage $52,500/day PDPR; claims to be submitted with full documents within 90 days of discharge.
From the SOFs: laytime consumed across load and discharge ports totals 171 hours (terminal congestion at the discharge port). Calculation: 171 − 84 = 87 hours on demurrage. 87 ÷ 24 = 3.625 days. 3.625 × $52,500 = $190,313 owed by the charterer to the owner.
Before the claim goes out, each of the 87 hours is checked against the CP's exclusions — if, say, 6 hours were a weather stop the CP excludes, the claim drops to $177,188 and survives scrutiny, instead of inviting a blanket challenge. Then: laytime statement, SOF and NOR attached, submitted well inside the 90-day bar.
Why this is an automation problem
An estimated ~99% of SOFs are still processed manually, each claim taking hours of analyst time — and a VLCC's demurrage rate was $45,000–$52,500/day in a normal 2025 market (Argus) and multiples of that during the 2026 Gulf disruption. Marevo's engine reads the CP and SOF, computes the statement, drafts the claim pack and counts down the time bar. The owner portal is live in demo at marevoapp.com.
Frequently asked
What does PDPR mean?
'Per day pro rata' — the demurrage rate is quoted per day but accrues by the hour (and minute). 87 hours at $52,500/day is 87/24 × 52,500.
What is despatch?
The mirror image of demurrage in some (mostly dry-bulk) charters: if the charterer finishes early, the owner pays despatch, customarily at half the demurrage rate. Tanker charters usually don't pay despatch — check the CP.
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