I need to work out how much material it will take to fill a human mould based on a certain set of figures that I have, and I don't know how to convert them.

The material covers 64.1m²/tonne @ a depth of 10mm.

The figures I have for the mould are: height 1.7m, and average diameter 0.82m (waist).

Please can someone show me how to work this out because I have worked it out to be 1.38t of material, and this seems rather high.

Thanking you in advance.