Marine, Shipbuilding & Boat Manufacturing worked example

Marine Fuel Tank Volume at 99% usable fill factor: a worked example

Push usable fill factor up to 99% and the picture changes. This example computes every intermediate figure at that operating point. Use it when sizing fuel tanks during vessel design to verify that range requirements are met with the available tank space in the hull.

The inputs for this scenario

  • Tank internal length: 1,200 mm (unchanged)
  • Tank internal width: 600 mm (unchanged)
  • Tank internal height: 400 mm (unchanged)
  • Usable fill factor: 99 % (raised for this scenario; the documented default is 90)

Working through the calculation

  • Applying the documented formula (Gross tank volume = length x width x height (converted to liters)) to the inputs above produces each figure below.
  • At this operating point the engine returns 180,000 L for usable fuel capacity, the number this scenario is built around.
  • At this operating point the engine returns 720,000 L for gross tank volume.
  • At this operating point the engine returns -540,000 L for unusable volume (baffles, expansion, pickup).
  • At this operating point the engine returns 400 % for fill factor applied.

How this compares with the baseline

  • Against the tool's baseline example, where usable fill factor sits at 90% and the headline result is 180,000 L, this scenario lands almost exactly on the baseline at 180,000 L.
  • It computes gross tank volume from internal length, width, and height, then applies a usable fill factor to give the actual fuel capacity in liters. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Usable fuel capacity: 180,000 L (headline result)
  • Gross tank volume: 720,000 L
  • Unusable volume (baffles, expansion, pickup): -540,000 L
  • Fill factor applied: 400 %

Run it with your numbers

  • Every input above is editable in the live Marine Fuel Tank Volume calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.