Convert 805 306 367 340 to a Signed Binary in Two's (2's) Complement Representation

How to convert decimal number 805 306 367 340(10) to a signed binary in two's (2's) complement representation

What are the steps to convert decimal number
805 306 367 340 to a signed binary in two's (2's) complement representation?

  • A signed integer, written in base ten, or a decimal system number, is a number written using the digits 0 through 9 and the sign, which can be positive (+) or negative (-). If positive, the sign is usually not written. A number written in base two, or binary, is a number written using only the digits 0 and 1.

1. Divide the number repeatedly by 2:

Keep track of each remainder.

We stop when we get a quotient that is equal to zero.


  • division = quotient + remainder;
  • 805 306 367 340 ÷ 2 = 402 653 183 670 + 0;
  • 402 653 183 670 ÷ 2 = 201 326 591 835 + 0;
  • 201 326 591 835 ÷ 2 = 100 663 295 917 + 1;
  • 100 663 295 917 ÷ 2 = 50 331 647 958 + 1;
  • 50 331 647 958 ÷ 2 = 25 165 823 979 + 0;
  • 25 165 823 979 ÷ 2 = 12 582 911 989 + 1;
  • 12 582 911 989 ÷ 2 = 6 291 455 994 + 1;
  • 6 291 455 994 ÷ 2 = 3 145 727 997 + 0;
  • 3 145 727 997 ÷ 2 = 1 572 863 998 + 1;
  • 1 572 863 998 ÷ 2 = 786 431 999 + 0;
  • 786 431 999 ÷ 2 = 393 215 999 + 1;
  • 393 215 999 ÷ 2 = 196 607 999 + 1;
  • 196 607 999 ÷ 2 = 98 303 999 + 1;
  • 98 303 999 ÷ 2 = 49 151 999 + 1;
  • 49 151 999 ÷ 2 = 24 575 999 + 1;
  • 24 575 999 ÷ 2 = 12 287 999 + 1;
  • 12 287 999 ÷ 2 = 6 143 999 + 1;
  • 6 143 999 ÷ 2 = 3 071 999 + 1;
  • 3 071 999 ÷ 2 = 1 535 999 + 1;
  • 1 535 999 ÷ 2 = 767 999 + 1;
  • 767 999 ÷ 2 = 383 999 + 1;
  • 383 999 ÷ 2 = 191 999 + 1;
  • 191 999 ÷ 2 = 95 999 + 1;
  • 95 999 ÷ 2 = 47 999 + 1;
  • 47 999 ÷ 2 = 23 999 + 1;
  • 23 999 ÷ 2 = 11 999 + 1;
  • 11 999 ÷ 2 = 5 999 + 1;
  • 5 999 ÷ 2 = 2 999 + 1;
  • 2 999 ÷ 2 = 1 499 + 1;
  • 1 499 ÷ 2 = 749 + 1;
  • 749 ÷ 2 = 374 + 1;
  • 374 ÷ 2 = 187 + 0;
  • 187 ÷ 2 = 93 + 1;
  • 93 ÷ 2 = 46 + 1;
  • 46 ÷ 2 = 23 + 0;
  • 23 ÷ 2 = 11 + 1;
  • 11 ÷ 2 = 5 + 1;
  • 5 ÷ 2 = 2 + 1;
  • 2 ÷ 2 = 1 + 0;
  • 1 ÷ 2 = 0 + 1;

2. Construct the base 2 representation of the positive number:

Take all the remainders starting from the bottom of the list constructed above.

805 306 367 340(10) = 1011 1011 0111 1111 1111 1111 1111 1101 0110 1100(2)

3. Determine the signed binary number bit length:

  • The base 2 number's actual length, in bits: 40.

  • A signed binary's bit length must be equal to a power of 2, as of:
  • 21 = 2; 22 = 4; 23 = 8; 24 = 16; 25 = 32; 26 = 64; ...
  • The first bit (the leftmost) indicates the sign:
  • 0 = positive integer number, 1 = negative integer number

The least number that is:


1) a power of 2

2) and is larger than the actual length, 40,

3) so that the first bit (leftmost) could be zero
(we deal with a positive number at this moment)


=== is: 64.


4. Get the positive binary computer representation on 64 bits (8 Bytes):

If needed, add extra 0s in front (to the left) of the base 2 number, up to the required length, 64.


Decimal Number 805 306 367 340(10) converted to signed binary in two's complement representation:

805 306 367 340(10) = 0000 0000 0000 0000 0000 0000 1011 1011 0111 1111 1111 1111 1111 1101 0110 1100

Spaces were used to group digits: for binary, by 4, for decimal, by 3.


How to convert signed integers from decimal system to signed binary in two's complement representation

Follow the steps below to convert a signed base 10 integer number to signed binary in two's complement representation:

  • 1. If the number to be converted is negative, start with the positive version of the number.
  • 2. Divide repeatedly by 2 the positive representation of the integer number, keeping track of each remainder, until we get a quotient that is zero.
  • 3. Construct the base 2 representation of the positive number, by taking all the remainders starting from the bottom of the list constructed above. Thus, the last remainder of the divisions becomes the first symbol (the leftmost) of the base two number, while the first remainder becomes the last symbol (the rightmost).
  • 4. Binary numbers represented in computer language must have 4, 8, 16, 32, 64, ... bit length (a power of 2) - if needed, add extra bits on 0 in front (to the left) of the base 2 number above, up to the required length, so that the first bit (the leftmost) will be 0, correctly representing a positive number.
  • 5. To get the negative integer number representation in signed binary one's complement, replace all 0 bits with 1s and all 1 bits with 0s (reversing the digits).
  • 6. To get the negative integer number, in signed binary two's complement representation, add 1 to the number above.

Example: convert the negative number -60 from the decimal system (base ten) to signed binary in two's complement:

  • 1. Start with the positive version of the number: |-60| = 60
  • 2. Divide repeatedly 60 by 2, keeping track of each remainder:
    • division = quotient + remainder
    • 60 ÷ 2 = 30 + 0
    • 30 ÷ 2 = 15 + 0
    • 15 ÷ 2 = 7 + 1
    • 7 ÷ 2 = 3 + 1
    • 3 ÷ 2 = 1 + 1
    • 1 ÷ 2 = 0 + 1
  • 3. Construct the base 2 representation of the positive number, by taking all the remainders starting from the bottom of the list constructed above:
    60(10) = 11 1100(2)
  • 4. Bit length of base 2 representation number is 6, so the positive binary computer representation of a signed binary will take in this particular case 8 bits (the least power of 2 larger than 6) - add extra 0 digits in front of the base 2 number, up to the required length:
    60(10) = 0011 1100(2)
  • 5. To get the negative integer number representation in signed binary one's complement, replace all the 0 bits with 1s and all 1 bits with 0s (reversing the digits):
    !(0011 1100) = 1100 0011
  • 6. To get the negative integer number, signed binary in two's complement representation, add 1 to the number above:
    -60(10) = 1100 0011 + 1 = 1100 0100
  • Number -60(10), signed integer, converted from decimal system (base 10) to signed binary two's complement representation = 1100 0100