Work out ballast water volume instantly with clear inputs, formula shown and shareable results.
Tank capacity is the geometric volume reduced by permeability, which accounts for the internal structure that displaces water. Mass follows from sea water density. The three-times-volume figure is the flow-through exchange requirement used to meet ballast water management standards.
Ballast volume
V = L x B x H x permeability; mass = V x 1.025 t/m3; flow-through exchange = 3 x V
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.
Frames, girders and stiffeners inside the tank occupy volume. 95-98% is typical for a ballast tank.
Pumping three times the tank volume through gives roughly 95% replacement of the original water, the accepted standard for the flow-through method.