Number & Math Converters

Binary, Roman numerals, fractions, and number-to-words—switch tabs below, then scroll down for how-to steps and examples.

Binary / Hex / Decimal

Number System Converter

Enter a value in any number system and instantly convert it to all other systems. Supports binary (base-2), decimal (base-10), hexadecimal (base-16), and octal (base-8).

Convert Between Number Systems

Enter a valid number in the selected base system

Number to Words

Number to Words Converter

Enter any number and instantly convert it to English words. Choose from different formats including currency, years, and decimal numbers.

Convert Numbers to Words

Enter any whole number (positive or negative, up to 66 digits)
Enter a decimal number with up to 15 decimal places
Enter a year (4-digit recommended, but any year accepted)

Roman Numerals

Roman ↔ Arabic Converter

enter value to convert

👉 Arabic number
Roman
🔁 Roman numeral

conversion

MMXXVI
2026 in Roman numerals

validated with classic Roman rules (subtractive notation)

How it works: Roman numerals use letters I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Modern standard uses subtractive principle (e.g., IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900).

Fraction ↔ Decimal

Fraction ↔ Decimal Converter

Enter a fraction, decimal, percentage, or mixed number to convert it to all other formats. Get simplified fractions and step-by-step explanations.

Convert Between Formats

3
4
Enter a decimal number (up to 6 decimal places)
Enter a percentage value (without the % sign)
1 1/2

Number & math converters — guide

This page groups four tools for computer science, maths class, and everyday writing. Use the tabs above or the left menu to switch tools.

How to use these tools

  1. Pick a tab: Binary/Hex, Number to Words, Roman, or Fraction ↔ Decimal.
  2. Enter your value in the input box.
  3. Choose options such as input base or language for words.
  4. Tap Convert and read the result; use Clear to start again.

Worked examples

Binary / hex: Decimal 42 → binary 101010, hex 2A. Use the Binary / Hex tab.
Number to words: 1250 → one thousand two hundred fifty. See Number to Words.
Roman: 2024 → MMXXIV on the Roman tab.
Fraction: 3/4 → 0.75 on the Fraction tab.

Explore related converters

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Common questions

What is binary?

Binary uses only 0 and 1. Computers use bits because circuits are on or off.

Can I convert large numbers to words?

Yes for normal homework sizes; very huge numbers may hit browser limits.