Work out ship displacement instantly with clear inputs, formula shown and shareable results.
Displacement is the mass of water the hull pushes aside, equal to the underwater volume times water density. That volume is length times beam times draft times the block coefficient, and sea water at 1.025 t/m3 makes a ship float about 2.5% higher than the same hull in fresh water.
Displacement
Volume = L x B x T x Cb; displacement = volume x 1.025 t/m3 in sea water
Marine results are planning estimates only. Verify against the vessel's approved stability booklet, loading manual, class society rules and applicable maritime regulations before loading or sailing.
Fresh water is less dense, so a greater volume must be displaced to support the same mass — the origin of the fresh water allowance on the load line.
Tonnes per centimetre tells you how much cargo changes the draft, which is the basis of a draft survey.