Binary Number Converter
Convert between decimal, binary, octal and hexadecimal instantly. Type in any format and see all conversions simultaneously.
Type a value in any field. All other bases update automatically.
DEC Decimal (Base 10)
BIN Binary (Base 2)
OCT Octal (Base 8)
HEX Hexadecimal (Base 16)
Bit Representation
Step-by-Step Decimal to Binary
Frequently Asked Questions
What is the binary number system?
The binary number system uses only two digits: 0 and 1. It is base 2, meaning each position in a binary number represents a power of 2 (1, 2, 4, 8, 16...). Computers store and process all data using binary internally.
How do you convert decimal to binary?
Repeatedly divide the decimal number by 2 and record the remainders. Read the remainders from bottom to top. For example: 13 ÷ 2 = 6 rem 1, 6 ÷ 2 = 3 rem 0, 3 ÷ 2 = 1 rem 1, 1 ÷ 2 = 0 rem 1. Reading bottom to top: 1101₂.
What is hexadecimal (hex)?
Hexadecimal (base 16) uses digits 0–9 and letters A–F. It is commonly used in computing, colour codes (e.g., #FF5733), memory addresses, and networking (MAC addresses). One hex digit represents exactly 4 binary digits (a nibble).
What is octal?
Octal (base 8) uses digits 0–7. It was historically used in computing and is still found in Unix file permissions (e.g., chmod 755 = 111 101 101 in binary). One octal digit represents exactly 3 binary digits.
Why is number base conversion important for WAEC/JAMB?
Number base conversion is a core topic in WAEC and JAMB mathematics. Students are expected to convert between bases 2, 8, 10, and 16, and to perform arithmetic in non-decimal bases. Mastering this topic is essential for high scores.