StudyDeck

Converting Between Binary & Denary

Exam code: 2210
Written by: Ashika|Reviewed by: Caroline Carroll|Updated 2 July 2026

Denary to Binary Conversion

Denary to Binary Conversion

How do you convert denary to binary?

  • It is important to know the process of converting from denary to binary to understand how computers interpret and process data

  • To convert from denary to binary you must start by writing out a binary number line

  • Find the first column heading with a value larger than the denary value you are converting

  • Write down each column heading to the right (not including the largest heading) until you reach 1

32,768

16,384

8,192

4,096

2,048

1,024

512

256

128

64

32

16

8

4

2

1

Example 1

  • To convert the denary number 45 to binary, start by writing out the binary number line

  • The first column heading larger than 45 is 64, so the number line would be:

32

16

8

4

2

1

 

 

 

 

 

 

  • Start at the leftmost empty column heading (32)

  • Divide column heading into denary number (how many times does 32 fit into 45?)

    • 1 time with 13 remaining

13

32

16

8

4

2

1

 1

 

 

 

 

 

  • Repeat with next column heading (how many times does 16 fit into 13?)

    • 0 times with 13 remaining

13

13

32

16

8

4

2

1

1

0

  • Repeat until all columns have a binary value

13

13

5

1

1

0

32

16

8

4

2

1

1

0

1

1

0

1

  • Denary 45 is 101101 in binary (6 bits)

Example 2

  • To convert the denary number 3059 to binary, start by writing out the binary number line

  • The first column heading larger than 3059 is 4096, so the number line would be:

2,048

1,024

512

256

128

64

32

16

8

4

2

1

  • Start at the leftmost empty column heading (2048)

  • Divide column heading into denary number (how many times does 2048 fit into 3059?)

    • 1 time with 1011 remaining

1011

2,048

1,024

512

256

128

64

32

16

8

4

2

1

1

  • Repeat with next column heading (how many times does 1024 fit into 1011?)

    • 0 times with 1011 remaining

1011

1011

2,048

1,024

512

256

128

64

32

16

8

4

2

1

1

0

  • Repeat until all columns have a binary value

1011

1011

499

243

115

51

19

3

3

3

1

0

2,048

1,024

512

256

128

64

32

16

8

4

2

1

1

0

1

1

1

1

1

1

0

0

1

1

  • Denary 3059 is 101111110011 in binary (12 bits)

Binary to Denary Conversion

Binary to Denary Conversion

  • To convert from binary to denary, count how many bits make up the value

  • Write out the column headings for the number of bits given from right to left

  • Add together any column heading with a value of 1 in the column

Example 1 (4 bits)

  • To convert the binary number 1011 to denary, start by writing out the binary headings from right to left

8

4

2

1

 

 

 

 

  • Write in the binary digits under the headings from left to right

8

4

2

1

1

0

1

1

  • Add together any column heading with a 1 under it

  • (1 x 8) + (1 x 2) + (1 x 1) = 11

  • Binary 1011 is 11 in denary 

Example 2 (8 bits)

  • To convert the binary number 01100011 to denary, start by writing out the binary headings from right to left

128

64

32

16

8

4

2

1

 

 

 

 

 

 

 

 

  • Write in the binary digits under the headings from left to right

128

64

32

16

8

4

2

1

0

1

1

0

0

0

1

1

  • Add together any column heading with a 1 under it

  • (1 x 64) + (1 x 32) + (1 x 2) + (1 x 1) = 99

  • Binary 01100011 is 99 in denary 

Example 3 (14 bits)

  • To convert the binary number 01110001110100 to denary, start by writing out the binary headings from right to left

8,192

4,096

2,048

1,024

512

256

128

64

32

16

8

4

2

1

0

1

1

1

0

0

0

1

1

1

0

1

0

0

  • Add together any column heading with a 1 under it

  • (1 x 4096) + (1 x 2048) + (1 x 1024) + (1 x 64) + (1 x 32) + (1 x 16) + (1 x 4) = 7284

  • Binary 01110001110100 is 7284 in denary