Marine, Shipbuilding & Boat Manufacturing worked example

Marine Fuel Tank Volume at 65% usable fill factor: a worked example

This worked example runs the marine fuel tank volume numbers for a tougher week than the baseline: 65% usable fill factor instead of the typical 90%. Calculate fuel tank usable volume from tank internal dimensions and a fill factor, then estimate range at a given fuel consumption rate for vessel design and owner specifications.

The inputs for this scenario

  • Tank internal length: 1,200 mm (held at the documented default)
  • Tank internal width: 600 mm (held at the documented default)
  • Tank internal height: 400 mm (held at the documented default)
  • Usable fill factor: 65 % (the input this scenario stresses; the baseline uses 90)

Working through the calculation

  • The calculation starts from the formula this tool documents: Gross tank volume = length x width x height (converted to liters).
  • Usable fuel capacity works out to 180,000 L at these inputs, and this is the headline figure for the scenario.
  • Gross tank volume works out to 720,000 L at these inputs.
  • Unusable volume (baffles, expansion, pickup) works out to -540,000 L at these inputs.
  • Fill factor applied works out to 400 % at these inputs.

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.
  • Use it when sizing or verifying a rectangular fuel or fresh-water tank during design, refit, or build. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of 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

  • To rerun this with your own numbers, open the live Marine Fuel Tank Volume calculator, set usable fill factor to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.