Bunker Fuel Calculator
Calculate fuel consumption and cost for a voyage from distance, speed, and daily consumption rate.
About this calculator
Voyage Duration is Voyage Distance divided by Average Speed (converted to a daily rate by multiplying speed in knots by 24 hours), giving the number of days at sea. Total Fuel Required multiplies that duration by Daily Consumption, then adds Sea Margin as a percentage buffer for weather, currents, and routing deviations that a straight-line distance calculation doesn't capture -- a real voyage rarely travels the theoretical shortest path at a perfectly steady speed. Because Voyage Duration scales inversely with Average Speed, a faster voyage burns less total fuel for the same distance even though it burns fuel at the same daily rate -- less time at sea means fewer days of consumption, despite ships typically burning MORE fuel per hour at higher speeds in reality (a real-world tradeoff this calculator's linear model doesn't capture, since Daily Consumption is a single fixed input rather than a function of speed).
Total Fuel Cost simply multiplies Total Fuel Required by Fuel Price -- Fuel Price has no effect on how much fuel the voyage actually consumes, only on what that fuel costs. CO₂ Emissions applies the standard IMO conversion factor of 3.114 tonnes of CO2 per tonne of heavy fuel oil burned -- the carbon conversion factor (Cf) for heavy fuel oil set out under MARPOL Annex VI, Regulation 22A, the same figure required in the IMO Data Collection System (DCS) and used throughout maritime emissions reporting frameworks including the Carbon Intensity Indicator (CII).
Inputs
Results
Total Fuel Required
572.9 MT
≈ 106 elephants
Total Fuel Cost
$343,750.00
≈ 8 Teslas
Figures current as of 2026. Source: MARPOL Annex VI, Regulation 22A (IMO Data Collection System), carbon conversion factor Cf = 3.114 for heavy fuel oil
How to Use This Calculator
- Enter the voyage distance in nautical miles and average speed in knots.
- Input daily fuel consumption in metric tons per day and the current bunker price per MT.
- Set the sea margin percentage (typically 5-15%) to account for adverse weather.
- Review total fuel required in MT, total fuel cost, and voyage duration in days.
- Check CO₂ emissions output for IMO DCS reporting and emissions planning.
How the result changes with Average Speed
| Average Speed | Total Fuel Required | Total Fuel Cost |
|---|---|---|
| 7 | 1,145.8 MT | $687,500.00 |
| 11 | 729.2 MT | $437,500.00 |
| 21 | 381.9 MT | $229,166.67 |
| 30 | 267.4 MT | $160,416.67 |
What each input means
- Voyage Distance
- Total voyage distance in nautical miles.
- Average Speed
- Average vessel speed over ground.
- Daily Consumption
- Main engine fuel consumption per day at sea.
- Fuel Price
- Current bunker fuel price per metric ton.
- Sea Margin
- Extra fuel allowance for weather, currents, and routing. Typical: 5-15%.
How this is calculated
Worked example, using the default values
- Identify Input Parameters5 parametersVoyage Distance = 5000, Average Speed = 14, Daily Consumption = 35, Fuel Price = 600, Sea Margin = 10 = 5 input(s) provided
- Calculate Voyage DurationVoyage Distance ÷ (Average Speed × 24)5000 ÷ (14 × 24) = 14.88 days
- Calculate Total Fuel Required(Voyage Duration × Daily Consumption) × (1 + Sea Margin ÷ 100)(14.88 × 35) × (1 + 10 ÷ 100) = 572.9 MT
- Calculate Total Fuel CostTotal Fuel Required × Fuel Price572.9 × 600 = $343,750
- Calculate CO₂ EmissionsTotal Fuel Required × 3.114572.9 × 3.114 = 1784.1 MT
Figures and sources
- Standard CO2 conversion factor for heavy fuel oil (IMO DCS/CII reporting) (2026) — MARPOL Annex VI, Regulation 22A (IMO Data Collection System), carbon conversion factor Cf = 3.114 for heavy fuel oil
Engine last updated . Checked against 1 independently-derived test — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does a faster voyage use less total fuel in this calculator?
Total Fuel Required is Daily Consumption multiplied by Voyage Duration, and Voyage Duration falls as Average Speed rises -- fewer days at sea means fewer days of fuel burn at the same daily rate. This calculator treats Daily Consumption as a single fixed input you supply, so it doesn't model the real-world tradeoff where a ship typically burns MORE fuel per hour steaming faster; if you want to compare speeds realistically, you'd need to re-enter a higher Daily Consumption figure for the faster speed rather than relying on one fixed value across different speeds.
Why doesn't Fuel Price affect Total Fuel Required?
Total Fuel Required is a physical quantity -- how many tonnes of fuel the voyage actually consumes -- determined entirely by distance, speed, daily consumption rate, and sea margin. Fuel Price only enters the calculation afterward, when Total Fuel Cost multiplies that physical fuel quantity by the price per tonne. Changing Fuel Price changes what the voyage costs, not how much fuel it burns.
What is Sea Margin, and why does it matter for a fuel estimate?
Sea Margin is a percentage buffer added on top of the theoretical fuel requirement to account for weather, currents, and routing deviations -- a ship rarely travels the exact great-circle distance at a perfectly constant speed, and adverse conditions increase fuel burn beyond the calm-water baseline. A typical Sea Margin is 5-15%, and this calculator applies it as a straightforward percentage increase on top of the base fuel calculation.
How is the CO₂ Emissions figure calculated?
It multiplies Total Fuel Required by 3.114, the standard IMO conversion factor for tonnes of CO2 emitted per tonne of heavy fuel oil (HFO) burned. This carbon conversion factor comes directly from MARPOL Annex VI, Regulation 22A, the same factor mandated for the IMO Data Collection System (DCS) and Carbon Intensity Indicator (CII), so this output can be compared directly against regulatory emissions reporting figures.
What isn't captured in this fuel and cost estimate?
This calculator uses a single fixed Daily Consumption figure for the entire voyage, so it doesn't model how fuel burn actually changes with speed, sea state, hull fouling, or cargo load -- all of which affect real-world consumption. It also doesn't account for port fees, canal transit charges, or fuel used in port versus at sea, so treat the result as a voyage fuel-leg estimate rather than a complete voyage operating cost.
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