Roman Numeral Converter
Convert numbers to Roman numerals and back (1 to 3999), with validation and a breakdown.
Result
How to use
- 1
Choose the direction.
- 2
Type a number or a Roman numeral.
- 3
See the converted value and how it is built up.
Questions
What are the Roman numeral symbols?
I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1000. A smaller symbol before a larger one is subtracted: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900.
Why does it stop at 3999?
Standard Roman numerals use at most three M's, so MMMCMXCIX (3999) is the largest. Larger numbers used a bar over a symbol to multiply it by 1000.
Is IIII valid?
Not in standard form — 4 is written IV. You may still see IIII on some clock faces.
About this Roman Numerals tool
Roman Numeral Converter — Convert numbers to Roman numerals and back (1 to 3999), with validation and a breakdown. It is one of 200 free tools on namasivayam.in, made by software engineer Namasivayam Vadivelan for everyday use in India.
Everything is calculated instantly in your browser: nothing you type or upload is sent to any server, there is no sign-up, and it works on mobile and desktop. Choose the direction.
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Results are estimates to help you plan. They are not financial, tax or medical advice.