Roman Numeral Converter

Tip: whole numbers only. Example: 1999 → MCMXCIX

Enter a value to convert.

Roman Numeral Converter (Numbers ↔ Roman Numerals)

Convert numbers to Roman numerals and Roman numerals to numbers in seconds. This guide includes a Roman numerals chart, the conversion rules (I, V, X, L, C, D, M), step-by-step examples, and a quick reference for years and dates (e.g., 2025 → MMXXV, 1999 → MCMXCIX). Ideal for homework, exams, clocks, page numbering, film credits, and historic dates.

Roman Numerals Explained

Roman numerals use seven symbols:

I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000
Numbers are formed by adding and, in some cases, subtracting values.
Standard “modern usage” covers 1–3999 (I to MMMCMXCIX).

Key idea: write the largest symbols first and add; place a smaller symbol before a larger one to subtract (e.g., IV = 4, IX = 9).

Roman Numerals Chart (Quick Reference)

1–20

1 I	2 II	3 III	4 IV	5 V	6 VI	7 VII	8 VIII	9 IX	10 X
11 XI	12 XII	13 XIII	14 XIV	15 XV	16 XVI	17 XVII	18 XVIII	19 XIX	20 XX

Tens to 100

| 30 XXX | 40 XL | 50 L | 60 LX | 70 LXX | 80 LXXX | 90 XC | 100 C |

Hundreds to 1000

| 200 CC | 300 CCC | 400 CD | 500 D | 600 DC | 700 DCC | 800 DCCC | 900 CM | 1000 M |

How to Convert Numbers to Roman Numerals (Step by Step)

Break the number into thousands, hundreds, tens, and ones.
Map each place using the standard patterns:

- Ones: I, II, III, IV, V, VI, VII, VIII, IX
- Tens: X, XX, XXX, XL, L, LX, LXX, LXXX, XC
- Hundreds: C, CC, CCC, CD, D, DC, DCC, DCCC, CM

Concatenate the parts.

Examples

- 58 → 50 (L) + 8 (VIII) = LVIII
- 944 → 900 (CM) + 40 (XL) + 4 (IV) = CMXLIV
- 2025 → 2000 (MM) + 20 (XX) + 5 (V) = MMXXV

How to Convert Roman Numerals to Numbers

Read from left to right.
If a symbol is followed by an equal or smaller value, add it.
If a symbol is followed by a larger value, subtract it.

Examples

MCMXCIX = 1000 + (900) + (90) + (9) = 1999
XL = 50 − 10 = 40
CD = 500 − 100 = 400

Subtractive Rules (Modern Usage)

Only I before V or X (4, 9)
Only X before L or C (40, 90)
Only C before D or M (400, 900)
No subtracting with V, L, D and no repeating a symbol more than three times in a row (e.g., IIII is not used; write IV).

Years & Dates in Roman Numerals

2025 → MMXXV
2024 → MMXXIV
1999 → MCMXCIX
1987 → MCMLXXXVII
1066 → MLXVI

For full dates (day-month-year), convert each number separately (e.g., 14/07/2025 → XIV / VII / MMXXV).

Common Mistakes to Avoid

Writing IIII for 4 (use IV) or VIIII for 9 (use IX).
Using VX for 5 (incorrect); V is already 5.
Placing more than three identical symbols in a row (e.g., XXXX).
Subtracting with the wrong letters (e.g., IL for 49 is wrong; correct is XLIX).

FAQs – Countdown Timer

Q: What is the Roman numeral for 0?
There is no zero in Roman numerals.

Q: What’s the largest number in standard Roman numerals?
By modern convention, pages and dates usually go up to 3999 (MMMCMXCIX). Larger values historically used overlines (vinculum) to multiply by 1,000, but that’s not common on the web.

Q: Why does 4 appear as IV and not IIII?
Subtractive notation avoids more than three repeats and shortens strings: IV (5 − 1) is preferred.

Q: How do I write 49, 90, 400, 900?
49 = XLIX, 90 = XC, 400 = CD, 900 = CM.

Q: How do I convert a year like 2020?
2020 = 2000 + 20 → MMXX.

Q: Are lowercase roman numerals valid?
Yes in text, but uppercase (I, V, X, L, C, D, M) is standard for numeration.

Roman Numeral Converter