Tools · Maritime · No sign-up

Laytime calculator

GENCON-style laytime, demurrage and despatch. Enter the charter party terms and the port events, get the statement figures and the calculation input as JSON. This is the same open-source engine that produces every MarOps statement, running in your browser.

Nothing leaves your browser. The engine loads once (about 7 MB, cached afterwards) and every calculation runs on your machine. No account, no upload, no usage log.

Charter party terms

Counting basis

NOR to start (hours)

Demurrage rate per day

Currency

Despatch

Despatch on

SHINC counts every hour: there are no weekly excepted periods, holidays or unless used to enter.

Reversible (pool all ports) Interruptions deducted on demurrage (CP exception)

Ports

Result

Fill in the terms and ports, then calculate. The worked example reproduces a hand-verified golden test: 6,000 mt at 2,000 mt/day, a 12-hour rain stoppage, one day of demurrage.

Need it as a signed statement?

Send the SOF and the charter party terms; you get an English PDF statement, an Excel working file and this same basis JSON within 24 hours, checked by a deck officer.

Laytime statement in 24 hours →

Rules the engine commits to

The same rules, every time.

Once on demurrage, always on demurrage

After the allowance is exhausted nothing is deducted: not rain, not a Sunday. Unless the charter party says otherwise, which is the tick box above.

Deductions are records, not numbers

Every interruption has a start and an end. Overlapping interruptions and excepted days are merged before counting, so a rain stoppage on a Sunday is never deducted twice.

No floats, no time zones

Whole seconds and decimal arithmetic; days to five decimals, money to two. All times are port local; convert before you enter them.

Open source, golden-tested

The engine is the laytime package on PyPI, MIT licensed. Its golden tests are never fixed by updating the expected value. Why that matters →