Roman Number Calculator

Roman Number Converter

Roman number converter is a free tool that shows the Roman numeral for any given integer. CREST's online Roman numeral calculator tool accelerates the calculating process and shows the Roman numeral in a matter of seconds.

What are Roman Numerals?

Roman numerals are a numeral system that originated in ancient Rome and was used throughout the Roman Empire. Roman numerals are a unique way used by Romans to write numbers. They had symbols that stood for different values and they could add or subtract these symbols to make different numbers. For example, Roman numerals I, II, III, IV, V, VI, VII, VIII, IX and X represent 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10, respectively, which we use to label classes in school.

List of Basic Roman Numerals

The list of all 7 basic Roman numerals is given below:

Roman Numerals Chart from 1 to 1000

Rules for Writing Roman Numerals

While writing Roman numerals, we have to follow the following rules:

→ When a smaller letter precedes a bigger letter, we should subtract the corresponding numerical values.
For example, in IX we observe that X > I, so IX = 10 - 1 = 9. Therefore, IX = 9.
→ When a smaller letter comes after a bigger letter, we should add the corresponding numerical values.
For example, in VI, we observe that V > I, so, VI = 5 + 1 = 6. Therefore, VI = 6.
→ If a letter repeats itself multiple times, the value of that letter will be added.
For example, XX = X + X = 10 + 10 = 20.
→ A letter can not be repeated more than three times and V, L, and D cannot be repeated, they appear only once.
For example, we cannot write VV or DD. XXXX is also wrong.

Solved Examples on Roman Numerals

Example 1: Convert 67 into Roman Numeral.

Solution: We know that 60 in Roman numerals can be written as LX where L = 50 and X = 10.
7 = 5 + 2 = VII ( V = 5, I = 1)
So, 67 = 60 + 7 = LXVII

Hence, The number 67 in Roman numerals is written as LXVII.

Example 2: Convert 2024 into Roman Numeral.

Solution: Let's first break down 2024.
2024 = 1000 + 1000 + 10 + 10 + 4
We know that M = 1000, X = 10, V = 5 and I = 1.
4 in Roman Numeral can be written as IV, as 4 = 5 - 1 = IV.
Using the above letters, let's write 2024 in Roman Numerals.
2024 = MMXXIV

Hence, the number 2024 in Roman numerals is written as MMXXIV.

Example 3: Simplify MMXXVI – XLV + IX.

Solution: We will use the basic letters of Roman numerals to simplify the above expression.
We know that M = 1000, X = 10, V = 5 and I = 1.
MMXXVI = 1000 + 1000 + 10 + 10 + 5 + 1 = 2026
XLV = XL + V = (50 - 10) + 5 = 45 (When a smaller letter precedes a bigger one, we should subtract the corresponding numerical values.)
IX = 10 - 1 = 9 (When a smaller letter precedes a bigger one, we should subtract the corresponding numerical values.)

Thus, MMXXVI – XLV + IX = 2026 - 45 + 9 = 1990

Frequently Asked Questions

1. How Can I Convert Roman Numerals to Arabic Numerals?

Answer: To convert Roman numerals to Arabic numerals (standard digits), just give values to each Roman numeral symbol and add or subtract as needed.
For example, IV = (5 - 1) = 4 and LX = L + X = 50 + 10 = 60.

2. How do I Perform Arithmetic Operations with Roman Numerals?

Answer: Arithmetic operations with Roman numerals include addition, subtraction, multiplication, and division.
For example, II + III = 2 + 3 = 5 = V and IX - VI = 9 - 6 = 3 = III.