How to write 1 in Roman numerals
Roman numerals are built place by place, from the largest value to the smallest. For 1 the places are 1 (ones).
- Write 1 as
I.
Joined together, I gives I.
1 digit by digit
| Place | Value | Numeral | Rule used |
|---|---|---|---|
| ones | 1 | I | one symbol |
Check I by reading it back
Reading I from left to right and adding the pieces: I = 1. Together that is 1, so I and 1 match.
Mistakes to avoid with I
- Only I, X and C may be placed before a larger symbol to subtract, so I never contains forms such as VX or LC.
- Read I as one number, not letter by letter: add the values left to right, except where a smaller symbol sits before a larger one.
Facts about the number 1
- 1 is an odd number.
- In binary 1 is
1and in hexadecimal it is1. - Written out, 1 is "one".
- The digits of 1 add up to 1.
- 1 is a perfect square (1 x 1).
Where you will see 1 in Roman numerals
People see the number 1 written as I on clock faces to mark the first hour of the day. Publishers also use it for front matter page numbering in books. This numeral is chosen because Roman letters give a classic look that separates preliminary pages from the main text.
Numbers near 1
FAQ
What is 1 in Roman numerals?
1 is written I in Roman numerals. It is built from I (1).
How do you write 1 in lowercase Roman numerals?
Lowercase Roman numerals use the same rules, so 1 is i. Lowercase is common for page numbers in a book's preface and for outline levels.
How do I convert any number to Roman numerals?
Split the number into thousands, hundreds, tens and ones, write each part with the symbols I, V, X, L, C, D and M, then join them from largest to smallest. Or paste it into the Roman numeral converter, which also converts back.
More roman numerals
- 2 (II): next page
- Roman numerals chart: the full list