Number Base Converter

Number Bases Explained

A number base (or radix) defines how many unique digits are used to represent numbers. We use base 10 (decimal) in everyday life because we have 10 fingers. Computers use base 2 (binary) because digital circuits have two states: on and off.

Binary (Base 2) in Computing

Binary uses only 0 and 1. Every piece of data in a computer — numbers, text, images, video — is ultimately stored and processed as binary. A single binary digit is a bit; 8 bits make a byte (values 0–255). Understanding binary is fundamental to computer science, networking, and low-level programming.

Hexadecimal (Base 16) in Web Development

Hexadecimal uses digits 0–9 and letters A–F. It is used extensively in web development for CSS colors (#FF0000 = red), memory addresses, Unicode code points (U+0041 = “A”), and MAC addresses. Each hex digit represents exactly 4 binary bits, making it a convenient shorthand.

Octal (Base 8) Use Cases

Octal uses digits 0–7. It was historically common in early computing systems and is still used in Unix/Linux file permissions (chmod 755) and some programming contexts. Each octal digit represents exactly 3 binary bits.

Frequently Asked Questions

How do I convert decimal to binary?

Divide by 2 repeatedly, recording remainders. Read remainders bottom-to-top. Example: 13 → 1101. Or type the number into this tool for instant conversion.

What is hexadecimal used for?

CSS colors (#FF0000), memory addresses, MAC addresses, Unicode code points, and compact representation of binary data. Each hex digit = 4 binary bits.

How do I convert binary to decimal?

Multiply each bit by its place value (powers of 2) and sum the results. Example: 1101 = 8+4+0+1 = 13.

What is base 10 in binary?

Decimal 10 = binary 1010, hex A, octal 12.

How do I convert a number to hex?

Divide by 16 repeatedly, using A–F for remainders 10–15. Example: 255 → FF. This tool converts instantly.