Ship ETA and fuel
calculator.
Work out time at sea, ETA in local time and UTC, fuel for the passage and the effect of a speed change. Free, no sign-up, works on a phone on board.
ETA and voyage fuel
Enter the distance, speed and departure time. Times are converted through UTC, so departure and arrival can be in different time zones.
Fuel at a different speed
A common rule of thumb: daily fuel consumption changes roughly with the cube of speed, so fuel for the whole passage changes roughly with the square of speed. Use it for planning, not for bunker orders.
Speed needed to arrive on time
The formulas
- Time (hours) = distance (nm) ÷ speed (knots). One knot is one nautical mile per hour.
- Fuel for the passage (t) = daily consumption (t/day) × time (hours) ÷ 24.
- Consumption at new speed ≈ consumption at reference speed × (new speed ÷ reference speed)³. This is an approximation; hull fouling, draught, weather and engine load change the real figure.
- Required speed = distance ÷ hours available.
This calculator is a planning aid. Always use the vessel's own performance data, weather routing and the Master's judgement for passage planning and bunker decisions.
Keep these records without the paperwork.
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