How to Convert Decimal to Binary, Octal, and Hexadecimal using Python?

Python provides built-in functions to convert decimal numbers to different number systems. These functions are bin() for binary, oct() for octal, and hex() for hexadecimal conversion.

Syntax

bin(number)    # Returns binary representation
oct(number)    # Returns octal representation  
hex(number)    # Returns hexadecimal representation

Basic Conversion Example

Here's how to convert a decimal number to different number systems ?

decimal = 27

print(bin(decimal), "in binary.")
print(oct(decimal), "in octal.")
print(hex(decimal), "in hexadecimal.")

0b11011 in binary.
0o33 in octal.
0x1b in hexadecimal.

Removing Prefixes

The built-in functions include prefixes (0b, 0o, 0x). To get clean output without prefixes ?

decimal = 42

binary = bin(decimal)[2:]      # Remove '0b' prefix
octal = oct(decimal)[2:]       # Remove '0o' prefix  
hexadecimal = hex(decimal)[2:] # Remove '0x' prefix

print(f"Binary: {binary}")
print(f"Octal: {octal}")
print(f"Hexadecimal: {hexadecimal}")

Binary: 101010
Octal: 52
Hexadecimal: 2a

Converting Multiple Numbers

You can convert multiple decimal numbers using a loop ?

numbers = [8, 16, 32, 64]

print("Decimal\tBinary\tOctal\tHex")
print("-" * 35)

for num in numbers:
    binary = bin(num)[2:]
    octal = oct(num)[2:]
    hexadecimal = hex(num)[2:]
    print(f"{num}\t{binary}\t{octal}\t{hexadecimal}")

Decimal	Binary	Octal	Hex
-----------------------------------
8	1000	10	8
16	10000	20	10
32	100000	40	20
64	1000000	100	40

Key Points

• bin() returns binary with '0b' prefix
• oct() returns octal with '0o' prefix
• hex() returns hexadecimal with '0x' prefix
• Use slicing [2:] to remove prefixes
• All functions accept positive integers

Conclusion

Python's bin(), oct(), and hex() functions provide easy decimal conversion to different number systems. Use slicing to remove prefixes when needed for clean output formatting.