i am receiving number from ADC naturally its in the form of hex,but i need display it as decimal so its need conversion or any other method pls help me
No. Your calculations is most definitely not in hex. Hexadecimal is a numeric base and happens when you want to represent a number. Before you represent it, the number has no numeric base.
It's irrelevant that the processor internally represent numbers in binary - to your code, they are just numbers. If a datasheet says 0x00 - 0xff or if it says 0 - 255 doesn't matter. That is just a representation of the number - 0xff or 255 or 0377 or 0b11111111 is still the same value. This is similar to how one liter of water is the same amount of water even if you call it 10dl or 100cl or 0.001m3 or 35.1951oz or 0.22gal.
So stop being so totally locked up on what numeric base a value is presented in.