Convert numbers to Roman numerals and back. Supports 1 to 3,999,999.
Convert
Result
equals
Step-by-Step Breakdown
Symbol
Value
Running Total
The Roman Numeral System
Basic Symbols
Symbol
Value
I
1
V
5
X
10
L
50
C
100
D
500
M
1,000
Rules
Repeat I, X, C, M up to 3 times to add (III = 3).
V, L, D are never repeated.
A smaller symbol before a larger one means subtract: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900.
Only I, X and C can be used to subtract.
For 4,000+ use a bar above a letter to multiply by 1,000: V̄ = 5,000.
Frequently Asked Questions
Roman numerals are a numeric system from ancient Rome using letters: I (1), V (5), X (10), L (50), C (100), D (500), M (1000). They are still used today for clock faces, book chapters, monarchs (Elizabeth II), Super Bowls and movie copyright dates.
Standard Roman numerals only go up to 3,999 (MMMCMXCIX). For larger numbers the Romans used a vinculum – a horizontal bar above a letter that multiplies its value by 1,000. So V̄ (V with a bar) = 5,000 and M̄ = 1,000,000. This converter uses the vinculum notation for numbers 4,000 and above.
2026 = MMXXVI. Break it down as MM (2,000) + XX (20) + VI (6).
Both forms have been used historically – IIII appears on many clock faces. However, the modern convention (used in schools and exams) is subtractive: when a smaller numeral appears before a larger one, you subtract. So IV = 5 − 1 = 4 and IX = 10 − 1 = 9. Only I, X and C can be used subtractively.
No. The Romans had no symbol for zero. The medieval scholar Bede used the word "nulla" (nothing) or the letter N when needed. The concept of zero as a numeral arrived in Europe much later from Indian mathematics via the Arabic world.