---
title: "Roman Numeral Converter for Numbers and Dates | Past Crumbs"
description: "Convert numbers 1 to 3999 and whole dates to Roman numerals and back. Checks your numerals and explains older forms like IIII on clocks and MDCCCC."
url: https://pastcrumbs.me/roman-numeral-dates/
---

Drawer IV · Numerals

# Roman numerals for numbers and dates

Read the year on a foundation stone, a title page or a film's closing credits, or write a date the Roman way. Type a number or a numeral: the converter works out which way to go and checks your numerals as you type.

## How Roman numerals work

Seven letters do all the work: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. Write the thousands first, then the hundreds, tens and units, and add them up: MDCCLII is 1000 + 700 + 50 + 2 = 1752. To save writing four of a letter, the standard form puts a smaller letter before a larger one to subtract it, but only in six pairs: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900). So 1999 is MCMXCIX, not IMM.

Older writing often used plain addition instead: IIII for 4, VIIII for 9, MDCCCC for 1900. Many clock faces still show IIII at four o'clock, and London's Admiralty Arch carries the year 1910 as MDCCCCX. The converter reads these forms and gives the standard one alongside.

For a whole date, write the day, month and year each in numerals, separated by dots or spaces: 14 September 1752 becomes XIV.IX.MDCCLII. Standard numerals stop at 3999, MMMCMXCIX.

## Questions

**Is there a Roman numeral for zero?**

No. The system has no symbol for zero, which is why the converter starts at 1.

**Why is IC wrong for 99?**

In the standard form only I, X and C subtract, and each only from the next two letters up: I from V and X, X from L and C, C from D and M. So 99 is XC + IX, written XCIX.

**Is IIII a mistake?**

Not in old writing or on a clock face, where it is a long-standing additive form. In modern standard numerals 4 is IV, so the converter shows both.

## Sources

- Wikipedia, [Roman numerals](https://en.wikipedia.org/wiki/Roman_numerals), and the references it cites: the standard subtractive pairs (4, 9, 40, 90, 400, 900), 3999 as the largest standard numeral, additive forms such as IIII, XXXX and CCCC used alongside the subtractive ones, IIII on clock faces, and MDCCCCX on Admiralty Arch.