Fuel Consumption

Estimate fuel consumption from engine power, SFOC, and voyage profile. Supports single-leg and multi-leg voyages with speed–power scaling.

Common Inputs
Single-Leg Consumption
Time = Distance / Speed · Total Power = PME(1 + margin) + Aux
Multi-Leg Voyage with Speed–Power Scaling
Typical n ≈ 3
Leg Distance (nm) Speed (kn) Remove
Fuel Consumption Result

Total distance: nm

Total time: h ( days)

Average speed: kn

Total energy: kWh

Total fuel: t

Daily fuel rate: t/day


Fuel Consumption Calculator for Ships & Voyages

Fuel consumption is one of the most critical operational parameters in marine engineering and voyage planning. It directly affects operating cost, emissions, charter performance, and compliance with efficiency indices. This calculator estimates total fuel consumption based on engine power, specific fuel oil consumption (SFOC), auxiliary load, and voyage profile.

What Is Fuel Consumption in Marine Engineering?

Marine fuel consumption represents the mass of fuel burned by a vessel’s propulsion and auxiliary systems over a given time or distance. It is typically expressed in tonnes per voyage, tonnes per day (TPD), or tonnes per nautical mile.

Consumption depends on engine efficiency, vessel speed, sea margin, auxiliary demand, and voyage duration. Even small changes in speed or power can lead to significant differences in total fuel burned.

Calculation Method Used

The calculator is based on standard marine engineering practice:

  • Energy consumption:
    Energy (kWh) = Total Power (kW) × Time (h)
  • Total power:
    Ptotal = PME × (1 + Sea Margin) + Paux
  • Fuel consumption:
    Fuel (t) = Energy (kWh) × SFOC (g/kWh) ÷ 1,000,000

Single-Leg vs Multi-Leg Voyages

For simple estimates, a single-leg calculation is sufficient when distance, speed, and main engine power are known for the entire voyage.

For more realistic scenarios, the multi-leg mode allows each voyage segment to be calculated separately. Engine power is scaled with speed using the classical propeller law:

P = Pref × (V / Vref)n, where the exponent n is typically close to 3 for displacement vessels.

Auxiliary Load & Sea Margin

Auxiliary and hotel loads are added as a constant power demand throughout the voyage. A sea margin can be applied to the main engine power to account for weather, fouling, and operational uncertainties.

Including these factors provides a more conservative and realistic fuel estimate compared to ideal calm-water conditions.

Typical Applications

  • Voyage planning and bunker estimation
  • Charter party performance calculations
  • Speed and fuel trade-off studies
  • Emission and efficiency reporting (EEOI, CO₂)
  • Operational cost comparison between routes

Important Notes

Results are estimates and depend on the accuracy of input data. Actual fuel consumption may vary due to weather, hull condition, engine tuning, and operational practices.

For compliance or contractual use, always verify calculations against approved onboard performance data and engine manufacturer documentation.