Conversions
Roman numerals
Convert both ways between decimal and Roman numerals. Range: 1 to 3999.
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Range: 1–3999
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How to use this tool
Roman numerals still appear in many places: centuries (16th → XVI), kings and popes (Louis XIV, John Paul II), clock faces, act numbers in plays. Reading relies on 7 symbols (I, V, X, L, C, D, M) combined by addition and subtraction. The subtractive rule (IV = 4) caps the standard range at 3999.
Concrete examples
- 2026 → MMXXVI
- 1999 → MCMXCIX
- LIV → 54
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Frequently asked questions
- Why no zero in Roman numerals?
- Romans had no symbol for zero — the concept came later with Arabic numerals. The range starts at I (1).
- How to write 4 and 9?
- By subtraction: IV (5 − 1) for 4, IX (10 − 1) for 9. Same for XL (40), XC (90), CD (400), CM (900).
- What about numbers above 3999?
- Extended notations exist with a horizontal bar to multiply by 1000 (V̄ = 5000), but they're rare and non-standard — this tool caps at 3999.
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