Конвертер римских чисел

Convert numbers to Roman numerals and Roman numerals to numbers, from 1 to 3,999 (3,999,999 with overlines), with the standard form of any numeral.

Обновлено 28 сентября 2026 г.Проверенные примеры: 8

Результат

MMXXVI

Значение: 2,026

2,026 is MMXXVI: MM = 2,000, XX = 20, VI = 6.

MMXXVI by place value

Как выполняется расчёт S

Split into place values
$2026 = 2000 + 20 + 6$
Write each place value
$2000 \to \text{MM},\quad 20 \to \text{XX},\quad 6 \to \text{VI}$
4s and 9s use subtraction: IV, IX, XL, XC, CD, CM.
Join the symbols
$2026 = \text{MMXXVI}$

О калькуляторе: Конвертер римских чисел

Roman numerals write numbers with seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. To convert a number, the converter splits it into thousands, hundreds, tens and ones and writes each place separately; a 4 or 9 puts a smaller letter before a larger one, so 40 is XL and 900 is CM. To read a numeral, it adds the letters from left to right and subtracts any letter that stands before a larger one.

The default, 2026, splits into 2000 + 20 + 6 and becomes MMXXVI. The usual uses are years on buildings and in film credits, clock faces, chapter numbers and outlines. Reading MCMXCIV gives 1000 + 900 + 90 + 4 = 1994.

Standard numerals stop at 3999 (MMMCMXCIX). With the overline option a bar multiplies letters by 1000, so V̅ = 5000, up to 3,999,999. Non-standard numerals such as IIII or IC are still read, and the standard spelling is shown next to the value.

Примеры с решением

2421

Перевод единиц: Number to Roman
Number: 2421

Результат: MMCDXXI
Значение: 2,421

Источник проверки: Wikipedia — Roman numerals, standard-form examples (2421 = MMCDXXI); Python greedy conversion (forkA/verify_roman.py)

1776 (Statue of Liberty tablet)

Перевод единиц: Number to Roman
Number: 1776

Результат: MDCCLXXVI

Источник проверки: Inscription JULY IV MDCCLXXVI on the Statue of Liberty's tablet; Python greedy conversion

3999, the largest standard numeral (edge)

Перевод единиц: Number to Roman
Number: 3999

Результат: MMMCMXCIX

Источник проверки: Wikipedia — Roman numerals: MMMCMXCIX is the largest number in standard form; Excel ROMAN(3999)

XLII to a number

Перевод единиц: Roman to number
Roman numeral: XLII

Результат: 42
Значение: 42
Standard Roman form: XLII

Источник проверки: XL = 40, II = 2; Python parser (forkA/verify_roman.py)

Вопросы

What is 2026 in Roman numerals?

MMXXVI: MM = 2000, XX = 20 and VI = 6. Years are converted one place at a time, so 1999 is MCMXCIX (1000 + 900 + 90 + 9) rather than MIM, and 2000 is simply MM. The same rule gives MDCCLXXVI for 1776, the year inscribed on the tablet held by the Statue of Liberty.

What is the largest Roman numeral?

In standard form the largest number is 3999, written MMMCMXCIX, because there is no letter for 5000 and a letter repeats at most three times. Excel's ROMAN function returns #VALUE! above 3999 for the same reason. Larger numbers used an overline (vinculum) that multiplies by 1000: V̅ is 5000 and I̅V̅ is 4000, which takes this converter up to 3,999,999.

Is 4 written IV or IIII?

IV is the standard form; IIII is the additive form, and both mean 4. Standard form uses only six subtractive pairs: IV, IX, XL, XC, CD and CM. Many clock faces still show IIII for four o'clock while using IX for nine, a practice that goes back to clocks such as the late 14th-century Wells Cathedral clock. The converter reads IIII as 4 and gives IV as the standard spelling.

Why is 99 written XCIX and not IC?

Standard form lets a letter be subtracted only from the next two larger letters: I from V and X, X from L and C, and C from D and M. So 99 is 90 + 9 = XC + IX = XCIX, and 49 is XLIX rather than IL. Excel's ROMAN function breaks the rule only on request: its form 4 writes 499 as ID, while the default form gives CDXCIX.

Is there a Roman numeral for zero?

No. The Roman system had no symbol for zero, so the converter starts at 1. Medieval scholars wrote the Latin word nulla ("none") instead: Dionysius Exiguus used it in 525, and around 725 Bede or a colleague abbreviated it to the letter N.

Насколько точен «Конвертер римских чисел»?

Точность зависит от введённых данных и допущений метода. Десятичная арифметика использует 50 значащих цифр, но оценки, численные методы и исходные данные могут быть менее точными; округление на экране не устраняет эти ограничения. Решённые примеры, проверенные по независимым источникам: 8. Например, «2421» проверяется по источнику Wikipedia — Roman numerals, standard-form examples (2421 = MMCDXXI); Python greedy conversion (forkA/verify_roman.py).

Откуда взята методика?

Wikipedia — Roman numerals (standard form); Microsoft Excel ROMAN and ARABIC functions.

Об этом калькуляторе

\begin{gathered}\text{I}=1,\ \text{V}=5,\ \text{X}=10,\ \text{L}=50,\ \text{C}=100,\ \text{D}=500,\ \text{M}=1000 \\ \text{a smaller symbol before a larger one is subtracted: IV} = 4,\ \text{XC} = 90\end{gathered}

Источники

Проверено по источникам

В калькулятор включены решённые примеры с ответами из независимых источников. Их количество: 8. Они входят в набор тестов, и вы также можете запустить их здесь.