Skip to main content
24 Calk24
Mathematics

Roman Numeral Converter

Convert Arabic numbers to Roman numerals and vice versa. Step-by-step explanation, free and no registration required.

Updated 2026 Data stays local Free

Result

---

Referenztabelle

I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1000

Note: These calculations are for informational purposes only and do not replace professional tax or financial advice. All information without guarantee.

FAQ

Frequently Asked Questions

How do Roman numerals work?

Roman numerals use letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Smaller values before larger ones are subtracted (IV=4, IX=9). Numbers are read left to right.

What is the largest number in Roman numerals?

Standard Roman numerals go up to 3,999 (MMMCMXCIX). Larger numbers use a vinculum (bar above) to multiply by 1,000, but this is rarely needed in modern usage.

Does the calculator show the working steps?

Yes. In addition to the final result the calculator displays the intermediate steps so you can follow the solution — ideal for school, university or homework.

Guide

Quick Answer

The Roman numerals calculator converts Arabic numbers into Roman numeral notation and vice versa.

What is the Roman Numeral Converter?

The Roman numerals calculator converts Arabic numbers into Roman numeral notation and vice versa.

How does the Roman Numeral Converter work?

Enter an Arabic number (1-3,999) or Roman numerals. The calculator converts to the other form. The subtractive rule (e.g. IV = 4) is correctly applied.

Key Data and Facts

Basic symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1,000. Subtractive rule: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900. Max. standard notation: 3,999 (MMMCMXCIX).

Step-by-Step Guide

How to use the Roman numeral calculator step by step: 1. Choose the input direction -- Arabic to Roman or Roman to Arabic. 2. Enter the number -- for Arabic numbers, enter a value between 1 and 3,999. For Roman numerals, enter the characters I, V, X, L, C, D, M. 3. Read the result -- the calculator displays the converted number immediately. 4. Understand the subtraction rule: a smaller character placed before a larger one is subtracted. IV = 5 - 1 = 4, IX = 10 - 1 = 9, XL = 50 - 10 = 40, XC = 100 - 10 = 90. 5. Addition rule: identical or descending characters are added. VIII = 5 + 1 + 1 + 1 = 8. A maximum of three identical characters in a row (III = 3, but 4 = IV, not IIII). Typical uses: years on buildings (MMXXVI = 2026), chapter and section numbering, clock faces. Tip: break large numbers down from left to right into thousands, hundreds, tens and units.

Calculation Example

Arabic 1994 to Roman: 1000=M, 900=CM, 90=XC, 4=IV — result: MCMXCIV. Roman CDLXVII to Arabic: 400+50+10+5+1+1 = 467.

Sources · E-E-A-T

Official sources

Calculations are based on applicable German laws and official data:

Full methodology at Methodology.

Mathematics

Related Calculators