Roman numeral converter number to roman and back

How to Use This Roman Numeral Converter

Roman numerals are built from seven letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Symbols are usually added together, but when a smaller symbol comes before a larger one it is subtracted — so IV is 4, not 6, and IX is 9. The system has no zero and works from 1 to 3999. The converter works both ways: a number to its Roman form, or a Roman numeral back to a number.

Formula Used

Values are built from M=1000, D=500, C=100, L=50, X=10, V=5, I=1, using subtractive pairs (CM=900, CD=400, XC=90, XL=40, IX=9, IV=4). Reading back, a smaller symbol before a larger one is subtracted.

Worked Example

Example: Number → Roman · Value 2026

2,000 = MM; 20 = XX; 6 = VI.
Put together: MMXXVI.
In reverse, MMXXVI reads back as 2026 — the converter works both ways.

Roman Numeral: MMXXVI

Frequently Asked Questions

Why is 4 written as IV and not IIII?

Subtractive notation: a smaller symbol before a larger one is subtracted, so IV is 5 − 1 = 4. It keeps numerals shorter, and it is the standard form used today.

What is the biggest number I can convert?

3,999 (MMMCMXCIX). The Roman system has no symbol for 5,000 in common use, and no zero at all, so the converter works from 1 to 3,999.

Is there a Roman zero?

No. The Romans had no symbol for zero, and no need for one in their counting. That is one reason the system was replaced for maths.

Roman Numeral Converter