concrete calulations

[meatbeast]

HI Everyone,

I'm bulding a shed base in my garden, 5m x 4m x 15cm, can someone pls check my calculations,
3 cubic meters , assuming i half fill it with hardcore then i need between 1.5 and 2 cubic meters of concrete ..... so
a wickes bag of ballast comes in at roughly 0.5 cubic meters, so I need 3 jumbo bags and a bit.... but the cement comes in at 25kg bags, but does not list the volume..... so how many 25kg bags of cement do I need to order? i make it about 28...
which makes it ;
mixer £13.80
cement 128
ballast 0.5 m3 135
£276.80
what do you guys think?
cheers,
John

 

[Alarm]

Calculator there with wheelbarrow shots.

http://www.cnci.org.za/Uploads/Concrete, Mortar and Plaster.pdf

 

[meatbeast]

Hi, thanks for the link, but I've looked at so many calculators on line my brains beginning to leak! Can anyone check my sums pls