🧮 Number System Converter
Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36, and to Roman, Greek, Hebrew, Chinese and Church Slavonic numerals, Gray code, BCD and two's complement. The input system is detected automatically, large numbers and fractions are supported, and everything runs in your browser.
Number

Number System Converter

Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36, and to Roman, Greek, Hebrew, Chinese and Church Slavonic numerals, Gray code, BCD and two's complement. The input system is detected automatically, large numbers and fractions are supported, and everything runs in your browser.

Supported systems

Binary
Base 2 uses only 0 and 1. It is how computers store data.
1994 → 11111001010
Octal
Base 8 uses digits 0–7. Common in Unix file permissions.
1994 → 3712
Decimal
Base 10, the everyday number system.
11111001010 (2) → 1994
Hexadecimal
Base 16 uses 0–9 and A–F. Used for colors, memory addresses and hashes.
1994 → 7CA
Base 2–36
Any base from 2 to 36 with digits 0–9 and letters A–Z, plus base 60.
1994 → 1JE (36)
Roman numerals
Letters I V X L C D M. Standard range 1–3999; larger numbers use an overline.
1994 → MCMXCIV
Greek numerals · Hebrew numerals · Church Slavonic numerals
Alphabetic numerals: Greek (Ionic), Hebrew gematria and Church Slavonic with titlo.
1994 → ͵αϡϟδʹ · א׳ תתקצד · ҂ацчд҃
Chinese numerals
Positional-style Chinese numerals with 十 百 千 万 亿, plus the financial form.
1994 → 一千九百九十四
Arabic-Indic digits · Persian digits · Devanagari digits
The same decimal number written with Arabic-Indic, Persian or Devanagari digits.
1994 → ١٩٩٤ · १९९४
BCD · Gray code · Two's complement · IEEE 754
BCD, Gray code, two's complement and IEEE 754 float32/float64 hex.
1994 → BCD 0001 1001 1001 0100
Mayan numerals · Babylonian cuneiform
Mayan base-20 glyphs (dots and bars, one digit per line) and Babylonian base-60 cuneiform (wedges): the oldest positional systems.
463 → 𝋡 𝋣 𝋣 · 𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹
Factorial base
Each digit is limited by its position: n = d₁·1! + d₂·2! + d₃·3! + … Used for permutations and the Lehmer code.
463 → 341010
Zeckendorf (Fibonacci)
Every whole number is a sum of non-consecutive Fibonacci numbers, written as bits with no two adjacent 1s.
463 → 1000101010010

When to use

  • Programming, debugging and reading memory dumps
  • Studying computer science and mathematics
  • Dates, chapters and clock faces in Roman numerals
  • Reading inscriptions and texts with Greek, Hebrew, Slavonic or Chinese numerals

How to use

  1. Type a number; use 0x, 0b or 0o prefixes, Roman letters or script digits if you like
  2. Leave auto-detect on, or choose the input system manually
  3. All results appear at once; copy any of them
  4. Press ⇡ on a result to use it as the new input

FAQ

How do I convert binary to decimal?
Choose binary (or type a 0b prefix) and enter the number. The decimal result is shown immediately. Each binary digit is a power of two: 1011 is 8 + 2 + 1 = 11.
How do Roman numerals work?
Seven letters carry the values I=1, V=5, X=10, L=50, C=100, D=500 and M=1000. A smaller letter before a larger one is subtracted (IV=4, CM=900). The tool covers 1 to 3,999,999 using an overline for thousands.
Which ranges do the numeral scripts support?
Roman: 1–3,999,999; Greek and Church Slavonic: 1–999,999; Hebrew: 1–9999 (not exact thousands); Chinese: below 10¹². These systems only handle positive whole numbers.
Are fractions and negative numbers supported?
Yes for positional systems: choose how many fraction digits to show; extra digits are truncated, not rounded. Negative numbers also give a two's complement result.
Why can't the tool tell if FF is hex?
Letters alone are ambiguous. Use the 0x prefix or choose hexadecimal as the input system.
Is my data sent to a server?
No. Everything is calculated in your browser.