Question

Opening the calculator to do such tiny stuff appears annoying to me ,and I strongly believe in ths saying “the more you know,the better!” so here I am asking you how to convert hexadecimal to decimal.

Till that moment I use the following formula:

Hex:        Decimal:
12          12+6
22          22+2*6
34          34+3*6
49          49+4*6
99          99+9*6

I get confused when I move on at higher numbers like C0 or FB

What is the formula(brain,not functional) that you’re using?

Answer 1

If you consider that hexadecimal is base 16, its actually quite easy:

Start from the least significant digit and work towards the most significant (right to left) and multiply the digit with increasing powers of 16, then sum the result.

For example:

0x12 = 2 + (1 * 16)
= 18

0x99 = 9 + (9 * 16)
= 153

Then, remember that A = 10, B = 11, C = 12, D = 13, E = 14 and F = 15

So,

0xFB = 11 + (15 * 16)
= 251