When a cargo owner asks for a freight rate, they receive a number. What most don’t see is the logic behind that number — and why rates vary so dramatically between vessels, routes, and market conditions.

This guide breaks down exactly how a voyage charter freight rate is calculated, from a shipbroker’s perspective.

What Is a Voyage Charter?

A voyage charter is a contract between a shipowner and a cargo owner for the transport of a specific cargo from one port to another. Unlike a time charter — where the charterer hires the vessel for a period — a voyage charter covers a single voyage. The freight rate is the all-in price per metric tonne for that movement.

For standard charter party terms, see the BIMCO Standard Charter Party Clauses.

The 5 Components of a Voyage Freight Rate

1. Voyage Distance and Fuel Cost

Fuel is the single largest variable in any voyage freight calculation. A Capesize bulk carrier (180,000–220,000 DWT) burns approximately 50–55 metric tonnes of fuel per day at sea speed of 13–14 knots.

Take the example of a bauxite voyage from Boffa, Guinea to Dubai, UAE — approximately 8,200 nautical miles. At 13.5 knots, the sea passage takes roughly 25–26 days. At a VLSFO bunker price of $550/MT, the fuel cost for the passage alone is approximately $743,600.

This is before any port costs, loading time or vessel expenses are factored in.

2. Port Costs

Every port call generates costs: pilotage, towage, port dues, berth fees and agency fees. Who pays these depends on the charter party terms:

Free D/A (Free Despatch and Agency): The shipowner absorbs port costs at both ends.
Liner Terms: Port costs are for the account of the cargo owner.

On a Capesize call at a West African port, total port costs can range from $150,000 to $300,000 per port, depending on the terminal and country.

3. Laytime and Demurrage

Laytime is the amount of time allowed in the charter party for loading and discharging. It is calculated based on the agreed loading/discharging rate.

At a rate of 20,000 MT per weather working day (PWWD SHINC), a 200,000 MT bauxite cargo requires 10 days of laytime for loading.

If the vessel exceeds this — due to port congestion, equipment failure or weather — demurrage applies. On a Capesize, demurrage is typically $25,000–$35,000 per day. A three-day delay at a congested terminal adds $75,000–$105,000 to the total voyage cost.

4. Vessel Operating Costs

Every freight rate must cover the shipowner’s daily operating expenses: crew wages, maintenance, hull and machinery insurance, P&I Club cover, and capital costs. For a modern Capesize, daily OPEX typically ranges from $7,000–$12,000/day — absorbed into the rate quoted.

5. Vessel Position and Ballast Leg

A vessel’s geographic position at the time of fixing is perhaps the most underappreciated element of freight pricing. The ballast leg — the distance the vessel must travel empty to reach the loading port — represents pure cost with no revenue.

This is why Marcenta tracks vessel positions on a daily basis. We identify which ships are open in the right region and approach only those who can quote competitively.

How the Final Rate Is Built

Once all voyage costs are modelled, the owner adds their profit margin — typically 5–15% above break-even. The shipbroker’s commission (1.25%–2.5% per side) is then factored in.

Example calculation:

• Total voyage cost: $1,800,000
• Cargo quantity: 200,000 MT
• Break-even rate: $9.00/MT
• Owner margin (10%): $0.90/MT
• Gross rate quoted: $9.90/MT

Why Work with an Independent Shipbroker?

An independent shipbroker does not own vessels or cargo. Their value lies in market intelligence — knowing which owners are open, where, at what price, and how to structure a deal that works for both sides.

At Marcenta Chartering & Shipping Ltd, we specialise in Capesize dry bulk across West Africa, Black Sea, Mediterranean and Continent. We work on a confidential basis with cargo owners and commodity traders.

📩 chartering@marcenta.co.uk | marcenta.co.uk