As an example,
If you have a hexadecimal value: 0x1234
Its decimal equivalent is: (starting from the right side, or the Least Significant Bit - LSB)
4*(16^0) + 3*(16^1) + 2*(16^2) + 1*(16^3)
= 4*1 + 3*16 + 2*256 + 1*4096
= 4 + 48 + 512 + 4096
= 4660
Hope this helps!
Cheers,
Kosh!