How could I get to know how much stone I could load per 20' container?

At Xiamen Port in China, we could load the maximum gross weight of 27 tons into one 20'container. Therefore, how much stone you could load per 20' container depends on the weight limit on the roads or railway of your country. The density of stone colors ranges from 2600 to 3000KGS per cubic meter. The marble is around 2600KGS per cubic meter. The granite is around 2700KGS per cubic meter except for black granite with a density of 3000KGS per cubic meter. Please note that there should be at least 1000KGS held for the weight of the wooden crates. Therefore, for America, the quantity per 20' container load is as follows.
3/8" thickness: 6459 sq.ft. 
3/4" thickness: 3229sq.ft
1 1/4" thickness: 2153 sq.ft. 
1 1/2" thickness: 1615sq.ft. 
2" thickness: 1292 sq.ft. 

For most of the European countries and Middle East, the quantity per 20'container load is as follows. 
1cm: 935M2
1.2cm: 772M2 
1.5cm: 617M2
2cm: 463M2 
2.5cm: 370M2
3cm: 309M2
4cm: 231M2 
5cm: 185M2