For sand coverage you should get around 12-13 sq m per tonne at a depth of 50mm
http://www.pavingexpert.com/calcbedd.htm
You my friend win the "awesome dude of the day" award.
thanks for everyones input
For sand coverage you should get around 12-13 sq m per tonne at a depth of 50mm
http://www.pavingexpert.com/calcbedd.htm
yes 5x5 as said in original post it is 25m squared