18 in Roman numerals is XVIII. Split 18 into place values, write each part, and join them. The converter below works for any number from 1 to 3999.
What Is 18 in Roman Numerals?
Read XVIII from left to right and add the values: X (10) + VIII (8) = 18.
Roman numerals also number book chapters, outlines, and the names of kings and popes.
Convert Any Number to Roman Numerals
18: Thousands, Hundreds, Tens and Ones
| Place | Value | Roman |
|---|---|---|
| Tens | 10 | X |
| Ones | 8 | VIII |
| Total | 18 | XVIII |
Write the parts in order from largest to smallest to get XVIII.
Roman Numeral Rules Behind XVIII
| Symbol | I | V | X | L | C | D | M |
|---|---|---|---|---|---|---|---|
| Value | 1 | 5 | 10 | 50 | 100 | 500 | 1000 |
- Add symbols from largest to smallest: VI = 5 + 1.
- Repeat I, X, C or M up to three times: XXX = 30.
- Put a smaller symbol before a larger one to subtract: IV = 4, IX = 9.
XVIII has no subtractive pair, so you only add the symbols from left to right.
Roman Numerals Close to 18
| Number | Roman numeral |
|---|---|
| 14 in Roman numerals | XIV |
| 15 in Roman numerals | XV |
| 16 in Roman numerals | XVI |
| 17 in Roman numerals | XVII |
| 19 in Roman numerals | XIX |
| 20 in Roman numerals | XX |
| 21 in Roman numerals | XXI |
| 22 in Roman numerals | XXII |
See the full list in the Roman numerals chart.
Quick Answers About XVIII
What is 18 in Roman numerals?
18 in Roman numerals is XVIII.
What is XVIII as a number?
XVIII equals 18.
How do you write 19 in Roman numerals?
19 in Roman numerals is XIX.
What is 17 in Roman numerals?
17 in Roman numerals is XVII.
Quick Summary
18 is XVIII. Split the number into thousands, hundreds, tens and ones, write each part, and join them in order.
