A voyage estimate compares expected income with the time and costs required to perform a voyage. It can support a freight idea, evaluate a cargo for a vessel or compare voyage employment with a time-charter alternative. Its reliability depends more on the assumptions than on the spreadsheet.
1. Build the complete route
Include the vessel's ballast leg from current position to loading port, the laden leg to discharge and any expected canal, strait or routing requirement. Sea distance should come from a maritime route rather than a straight-line calculation. Add realistic allowances for traffic separation, weather routing and operational deviation where relevant.
2. Estimate sea and port time
Sea days are distance divided by speed and 24. Use separate ballast and laden speeds where the vessel data supports them. Port time should reflect cargo quantity, loading and discharging rates, working-time terms, expected waiting, shifting, bunkering and clearance.
| Time component | Typical inputs |
|---|---|
| Ballast sea time | Ballast distance and realistic ballast speed |
| Laden sea time | Laden distance and realistic laden speed |
| Loading time | Quantity, load rate and laytime qualification |
| Discharge time | Quantity, discharge rate and laytime qualification |
| Waiting and margin | Congestion, weather, canal and operational uncertainty |
3. Calculate bunker exposure
Apply the vessel's consumption to each operating mode: ballast at sea, laden at sea, idle in port and working in port. Keep fuel grades separate and use the intended bunker port price. Include expected remaining-on-board quantities only when they are part of the commercial comparison.
4. Add voyage costs
- Port disbursements at loading and discharge
- Canal, strait, pilotage and towage costs
- Stevedoring or terminal costs according to FIOST, FILO, LIFO or LILO basis
- Agency, survey, security, war-risk and environmental charges where applicable
- Brokerage, address commission and other agreed deductions
- Contingency for assumptions that remain unconfirmed
5. Test freight and return
Freight income is normally quantity multiplied by the freight rate, or a lump-sum amount where agreed. Deduct commissions and voyage costs to obtain the voyage contribution. Divide the contribution by total voyage days to estimate a time-charter equivalent. Compare several freight, speed, bunker and waiting scenarios rather than relying on one point estimate.
Pre-fixture checks
- Confirm cargo quantity and vessel intake.
- Confirm laycan instead of inventing a date.
- Validate loading and discharge rates and terms.
- Refresh bunker and port-cost inputs.
- Check route restrictions, draft and seasonal limits.
- Run downside cases for delay, consumption and reduced intake.
- Record the source and time of each market input.