The Seven Roman Numeral Symbols
Roman numerals use seven letters from the Latin alphabet. Each letter represents a fixed value. All numbers from 1 to 3,999 can be expressed by combining these seven symbols:
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1,000
In addition, six subtractive pairs are recognised in standard notation: IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900). These prevent a symbol from being repeated more than three times in a row.
How to Read Roman Numerals
Reading Roman numerals follows two rules applied left-to-right:
Additive rule
When a symbol is followed by one of equal or lesser value, add the values together. For example, VII = 5 + 1 + 1 = 7, and LX = 50 + 10 = 60.
Subtractive rule
When a smaller symbol appears immediately before a larger one, subtract the smaller from the larger. Only these six subtractive combinations are valid: IV (4), IX (9), XL (40), XC (90), CD (400), CM (900). For example, XIV = 10 + (5 − 1) = 14, and XL = 50 − 10 = 40.
Common Roman Numerals (1–100)
The table below lists all integers from 1 to 100 expressed as Roman numerals for quick reference.
| No. | Roman | No. | Roman | No. | Roman | No. | Roman | No. | Roman |
|---|---|---|---|---|---|---|---|---|---|
| 1 | I | 21 | XXI | 41 | XLI | 61 | LXI | 81 | LXXXI |
| 2 | II | 22 | XXII | 42 | XLII | 62 | LXII | 82 | LXXXII |
| 3 | III | 23 | XXIII | 43 | XLIII | 63 | LXIII | 83 | LXXXIII |
| 4 | IV | 24 | XXIV | 44 | XLIV | 64 | LXIV | 84 | LXXXIV |
| 5 | V | 25 | XXV | 45 | XLV | 65 | LXV | 85 | LXXXV |
| 6 | VI | 26 | XXVI | 46 | XLVI | 66 | LXVI | 86 | LXXXVI |
| 7 | VII | 27 | XXVII | 47 | XLVII | 67 | LXVII | 87 | LXXXVII |
| 8 | VIII | 28 | XXVIII | 48 | XLVIII | 68 | LXVIII | 88 | LXXXVIII |
| 9 | IX | 29 | XXIX | 49 | XLIX | 69 | LXIX | 89 | LXXXIX |
| 10 | X | 30 | XXX | 50 | L | 70 | LXX | 90 | XC |
| 11 | XI | 31 | XXXI | 51 | LI | 71 | LXXI | 91 | XCI |
| 12 | XII | 32 | XXXII | 52 | LII | 72 | LXXII | 92 | XCII |
| 13 | XIII | 33 | XXXIII | 53 | LIII | 73 | LXXIII | 93 | XCIII |
| 14 | XIV | 34 | XXXIV | 54 | LIV | 74 | LXXIV | 94 | XCIV |
| 15 | XV | 35 | XXXV | 55 | LV | 75 | LXXV | 95 | XCV |
| 16 | XVI | 36 | XXXVI | 56 | LVI | 76 | LXXVI | 96 | XCVI |
| 17 | XVII | 37 | XXXVII | 57 | LVII | 77 | LXXVII | 97 | XCVII |
| 18 | XVIII | 38 | XXXVIII | 58 | LVIII | 78 | LXXVIII | 98 | XCVIII |
| 19 | XIX | 39 | XXXIX | 59 | LIX | 79 | LXXIX | 99 | XCIX |
| 20 | XX | 40 | XL | 60 | LX | 80 | LXXX | 100 | C |
Rules for Writing Roman Numerals
Standard Roman numeral notation follows four main rules:
Rule 1 — Repetition limit
The symbols I, X, C, and M may be repeated up to three times in a row (e.g. III = 3, XXX = 30). The symbols V, L, and D may never be repeated.
Rule 2 — Subtractive notation
To avoid four repetitions, use a subtractive pair instead: IV instead of IIII, IX instead of VIIII, XL instead of XXXX, and so on. Only the six standard pairs (IV, IX, XL, XC, CD, CM) are valid.
Rule 3 — Descending order
Symbols are generally written from largest to smallest, left to right. A smaller symbol before a larger one signals subtraction; otherwise values are added.
Rule 4 — No zero
Roman numerals have no symbol for zero. The system can represent integers from 1 to 3,999 in standard form. The Romans used the Latin word nulla to convey the concept of "nothing."