According to the Amateur Gardening Hellyer Pocket Guide
(ISBN 0-600-56796-3), a very handy book containing all sorts of similar
data, it can be estimated as follows:-
Estimating soil for filling; Soil for filling up beds, etc., varies in
bulk according to its texture and the amount of water it contains.
Sandy soils are the lightest and may reach 1 cubic metre to the tonne
(26 to 27 cubic feet to the ton) while heavy clay soil barely touches
0.6 cubic metre (18 cubic feet) for the same weight.
The average for good fibrous loam is about 0.8 cubic metres to the
tonne, (23 to 24 cubic feet to the ton).
Hope this helps. Sorry if it has already been answered but Demon News
isn't playing today.
--
Hugh Simmons
hu...@st-ronan.demon.co.uk