How to Convert kg to m3

150kg of what? Air? Gold? Water?

Volume (m³) = mass(kg) ÷ density (kgm^-3)

Hi, All

150kg of concrete sand

Dry or wet ? How much humidity ?

The average for Southern Hemisphere sands are;

Sand, wet

1922

Sand, wet, packed

2082

Sand, dry

1602

Sand, loose

1442

Sand, rammed

1682

Sand, water filled

1922

Sand with Gravel, dry

1650

Sand with Gravel, wet

2020

'Scuse me being thick, but what do those numbers mean?

kg/cub m

What should do the "guest" if he is in the Northern Hemisphere ? Are those values in kg/m^3 or are they the year when the sand was formed ?

You take the piece, prepare a reservoir with water and pur the piece in totally. You measure the height variation of the water level and multiply by the free area the result in volume units the piece volume you want to determine. You can also use same procedure to determine the specific weight of the part by measuring weight in air and in water. Somebody did it a couple of thousand years ago his name Archimedes.