Convert 1 000 010 999 999 950 to a Signed Binary in Two's (2's) Complement Representation

How to convert decimal number 1 000 010 999 999 950(10) to a signed binary in two's (2's) complement representation

What are the steps to convert decimal number
1 000 010 999 999 950 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;
  • 1 000 010 999 999 950 ÷ 2 = 500 005 499 999 975 + 0;
  • 500 005 499 999 975 ÷ 2 = 250 002 749 999 987 + 1;
  • 250 002 749 999 987 ÷ 2 = 125 001 374 999 993 + 1;
  • 125 001 374 999 993 ÷ 2 = 62 500 687 499 996 + 1;
  • 62 500 687 499 996 ÷ 2 = 31 250 343 749 998 + 0;
  • 31 250 343 749 998 ÷ 2 = 15 625 171 874 999 + 0;
  • 15 625 171 874 999 ÷ 2 = 7 812 585 937 499 + 1;
  • 7 812 585 937 499 ÷ 2 = 3 906 292 968 749 + 1;
  • 3 906 292 968 749 ÷ 2 = 1 953 146 484 374 + 1;
  • 1 953 146 484 374 ÷ 2 = 976 573 242 187 + 0;
  • 976 573 242 187 ÷ 2 = 488 286 621 093 + 1;
  • 488 286 621 093 ÷ 2 = 244 143 310 546 + 1;
  • 244 143 310 546 ÷ 2 = 122 071 655 273 + 0;
  • 122 071 655 273 ÷ 2 = 61 035 827 636 + 1;
  • 61 035 827 636 ÷ 2 = 30 517 913 818 + 0;
  • 30 517 913 818 ÷ 2 = 15 258 956 909 + 0;
  • 15 258 956 909 ÷ 2 = 7 629 478 454 + 1;
  • 7 629 478 454 ÷ 2 = 3 814 739 227 + 0;
  • 3 814 739 227 ÷ 2 = 1 907 369 613 + 1;
  • 1 907 369 613 ÷ 2 = 953 684 806 + 1;
  • 953 684 806 ÷ 2 = 476 842 403 + 0;
  • 476 842 403 ÷ 2 = 238 421 201 + 1;
  • 238 421 201 ÷ 2 = 119 210 600 + 1;
  • 119 210 600 ÷ 2 = 59 605 300 + 0;
  • 59 605 300 ÷ 2 = 29 802 650 + 0;
  • 29 802 650 ÷ 2 = 14 901 325 + 0;
  • 14 901 325 ÷ 2 = 7 450 662 + 1;
  • 7 450 662 ÷ 2 = 3 725 331 + 0;
  • 3 725 331 ÷ 2 = 1 862 665 + 1;
  • 1 862 665 ÷ 2 = 931 332 + 1;
  • 931 332 ÷ 2 = 465 666 + 0;
  • 465 666 ÷ 2 = 232 833 + 0;
  • 232 833 ÷ 2 = 116 416 + 1;
  • 116 416 ÷ 2 = 58 208 + 0;
  • 58 208 ÷ 2 = 29 104 + 0;
  • 29 104 ÷ 2 = 14 552 + 0;
  • 14 552 ÷ 2 = 7 276 + 0;
  • 7 276 ÷ 2 = 3 638 + 0;
  • 3 638 ÷ 2 = 1 819 + 0;
  • 1 819 ÷ 2 = 909 + 1;
  • 909 ÷ 2 = 454 + 1;
  • 454 ÷ 2 = 227 + 0;
  • 227 ÷ 2 = 113 + 1;
  • 113 ÷ 2 = 56 + 1;
  • 56 ÷ 2 = 28 + 0;
  • 28 ÷ 2 = 14 + 0;
  • 14 ÷ 2 = 7 + 0;
  • 7 ÷ 2 = 3 + 1;
  • 3 ÷ 2 = 1 + 1;
  • 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.

1 000 010 999 999 950(10) = 11 1000 1101 1000 0001 0011 0100 0110 1101 0010 1101 1100 1110(2)

3. Determine the signed binary number bit length:

  • The base 2 number's actual length, in bits: 50.

  • 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, 50,

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 1 000 010 999 999 950(10) converted to signed binary in two's complement representation:

1 000 010 999 999 950(10) = 0000 0000 0000 0011 1000 1101 1000 0001 0011 0100 0110 1101 0010 1101 1100 1110

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