How to convert float number to Binary?

Consider below example

Convert 2.625 to binary.

We will consider the integer and fractional part separately.

The integral part is easy, 2 = 10. 

For the fractional part:

0.625   × 2 =   1.25    1   Generate 1 and continue with the rest.
0.25    × 2 =   0.5     0   Generate 0 and continue.
0.5     × 2 =   1.0     1   Generate 1 and nothing remains.

So 0.625 = 0.101, and 2.625 = 10.101.

See this link for more information.

Keep multiplying the number after decimal by 2 till it becomes 1.0:

0.25*2 = 0.50
0.50*2 = 1.00

and the result is in reverse order being .01

(d means decimal, b means binary)

1. 12.25d is your float.
2. You write 12d in binary and remove it from your float. Only the remainder (.25d) will be left.
3. You write the dot.
4. While the remainder (0.25d) is not zero (and/or you want more digits), multiply it with 2 (-> 0.50d), remove and write the digit left of the dot (0), and continue with the new remainder (.50d).