<-- Enter Number or Notation that will be converted
Conversion TypeBinaryOctalHexadecimalBase
Convert Decimal to:
 Base: 
Convert to Decimal from:
  

Answer
Success!
We are done. 81 converted from decimal to binary notation equals 10100012.

↓Steps Explained:↓

Convert 81 from decimal to binary

(base 2) notation:

Power Test

Raise our base of 2 to a power

Start at 0 and increasing by 1 until it is >= 81

20 = 1

21 = 2

22 = 4

23 = 8

24 = 16

25 = 32

26 = 64

27 = 128 <--- Stop: This is greater than 81

Since 128 is greater than 81, we use 1 power less as our starting point which equals 6

Build binary notation

Work backwards from a power of 6

We start with a total sum of 0:


26 = 64

The highest coefficient less than 1 we can multiply this by to stay under 81 is 1

Multiplying this coefficient by our original value, we get: 1 * 64 = 64

Add our new value to our running total, we get:
0 + 64 = 64

This is <= 81, so we assign our outside coefficient of 1 for this digit.

Our new sum becomes 64

Our binary notation is now equal to 1


25 = 32

The highest coefficient less than 1 we can multiply this by to stay under 81 is 1

Multiplying this coefficient by our original value, we get: 1 * 32 = 32

Add our new value to our running total, we get:
64 + 32 = 96

This is > 81, so we assign a 0 for this digit.

Our total sum remains the same at 64

Our binary notation is now equal to 10


24 = 16

The highest coefficient less than 1 we can multiply this by to stay under 81 is 1

Multiplying this coefficient by our original value, we get: 1 * 16 = 16

Add our new value to our running total, we get:
64 + 16 = 80

This is <= 81, so we assign our outside coefficient of 1 for this digit.

Our new sum becomes 80

Our binary notation is now equal to 101


23 = 8

The highest coefficient less than 1 we can multiply this by to stay under 81 is 1

Multiplying this coefficient by our original value, we get: 1 * 8 = 8

Add our new value to our running total, we get:
80 + 8 = 88

This is > 81, so we assign a 0 for this digit.

Our total sum remains the same at 80

Our binary notation is now equal to 1010


22 = 4

The highest coefficient less than 1 we can multiply this by to stay under 81 is 1

Multiplying this coefficient by our original value, we get: 1 * 4 = 4

Add our new value to our running total, we get:
80 + 4 = 84

This is > 81, so we assign a 0 for this digit.

Our total sum remains the same at 80

Our binary notation is now equal to 10100


21 = 2

The highest coefficient less than 1 we can multiply this by to stay under 81 is 1

Multiplying this coefficient by our original value, we get: 1 * 2 = 2

Add our new value to our running total, we get:
80 + 2 = 82

This is > 81, so we assign a 0 for this digit.

Our total sum remains the same at 80

Our binary notation is now equal to 101000


20 = 1

The highest coefficient less than 1 we can multiply this by to stay under 81 is 1

Multiplying this coefficient by our original value, we get: 1 * 1 = 1

Add our new value to our running total, we get:
80 + 1 = 81

This = 81, so we assign our outside coefficient of 1 for this digit.

Our new sum becomes 81

Our binary notation is now equal to 1010001


Final Answer

We are done. 81 converted from decimal to binary notation equals 10100012.
Take the Quiz


Related Calculators:  Bit Shifting  |  RGB and HEX conversions  |  Stoichiometry Conversion