[Regulation 7]
1. Multiply together the Registered Length, Registered Breadth and Registered Depth in metres and multiply the product by the factor 0.16. The result shall be the Registered Tonnage of the vessel, except for those vessels to which paragraph 2 also applies.
2. For vessels with a break or breaks above the line of deck multiply together the mean length, mean breadth and mean depth in metres of the space or each of the spaces thereby formed, then multiply the product for each space so measured by the factor 0.35 and add the results to the figure obtained by the calculation set out in paragraph 1. For such vessels the final result shall be the Registered Tonnage of the vessel.