ToolWren › Roman Numerals

Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals back to numbers, for years, names, clocks and outlines.

100% client-side · nothing is uploaded

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How to use the Roman Numerals

Enter the number you want to convert in the Value field.
Pick the unit you're converting From and the unit you want To.
Read the converted result, or use ⇅ to swap the two units.
Check the All units table to see your value expressed in every supported unit at once.

Privacy: this tool runs entirely in your browser. Your input is never sent to, received by, or stored on any server — there are no uploads and no tracking of what you enter.

About Roman Numerals

How Roman numerals work

Roman numerals combine letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Smaller before larger means subtract (IV=4, IX=9).

The range

Standard Roman numerals cover 1 to 3999. There is no zero and no standard way to write very large numbers without extensions.

Where you see them

Clock faces, book chapters, movie copyright years, monarch names (Henry VIII) and the Super Bowl.

Frequently asked questions

What is the largest Roman numeral?

In standard form, 3999 (MMMCMXCIX).

Is there a Roman zero?

No — the Romans had no symbol for zero.

How is 2024 written?

MMXXIV.