Number Base Converter — Binary, Decimal, Hex, Octal

Convert whole numbers between binary, octal, decimal and hexadecimal instantly, with a full base reference table.

🔢

Number Base Converter

Numbers • binary · octal · decimal · hex

🔢
Enter a value to convert

How to Use the Number Base Converter

  1. Enter a value — type any number. Invalid text and symbols are blocked automatically.
  2. Select From and To units — choose the units to convert between.
  3. Read the animated result — the converted value, factor, and full reference table update instantly.
  4. Use Swap (⇄) — reverse the conversion in one click.

Why Use This Number Base Converter

🎯

Accurate Standards

Built on internationally recognised SI and standards-body conversion factors for dependable results.

Instant & Animated

Results update live as you type, with a clear visual breakdown across every unit at once.

🔒

100% Private

Everything runs in your browser — no account, no uploads, nothing leaves your device.

Understanding the Number Base Converter

Programmers and students constantly convert between number systems: binary (base 2, used by digital hardware), octal (base 8), decimal (base 10, everyday numbers) and hexadecimal (base 16, used for colors, memory addresses and byte values). This converter handles all four directions and shows the value in every base at once.

Common examples: decimal 255 = binary 11111111 = octal 377 = hex FF. Decimal 16 = hex 10. The hex color #FFFFFF is three bytes, each 255 in decimal.

Number Base Converter FAQ

Repeatedly divide by 2 and record the remainders bottom-to-top, or just type the decimal number above and select "Binary" as the target. Example: 13 = 1101 in binary.
FF in hex equals 255 in decimal (15×16 + 15). One hex digit represents 4 bits, so two hex digits = one byte = 0–255.
Conversions are exact up to 2⁵³ (about 9.0 quadrillion), the safe-integer limit for precise calculation in the browser. Larger inputs are rejected to avoid rounding errors.

Related Converters

✔ Reviewed by the True Value Calc editorial team🗓 Last updated June 2026📚 Sources: NIST, BIPM SI unit definitions