2021 in Roman Numerals
2021 is MMXXI, two thousands, two tens, one unit, about as tidy as a numeral gets.
How MMXXI is formed
M + M + X + X + I = 1000 + 1000 + 10 + 10 + 1 = 2021.
Where MMXXI is used
A year numeral turns up in different places from a bare number. These are the four that send people looking for MMXXI.
- Date tattoos and engravings. A year-only piece is just MMXXI, and a full date stacks the day and month above it. MMXXI is 5 characters long, which matters more than people expect: it sets how wide the bottom line of a stacked date will sit.
- Copyright lines in credits. Film and television end credits have long set the copyright year in Roman numerals, so a production from 2021 carries MMXXI on its end card. If you are reading a numeral off a title sequence rather than writing one, this is usually the one you have found.
- Cornerstones and dedications. Buildings, monuments and foundation stones carry their year in numerals, which is why MMXXI turns up carved rather than typed. Every year between 2000 and 2099 opens with MM, so on a datestone it is the letters after MM that tell you which year you are actually looking at.
- Anniversaries. In 2026, a date from 2021 is 5 years old, so MMXXI is the numeral for a 5th anniversary this year. Wedding and birth years are the two most common reasons to want MMXXI written correctly.
Convert another year or number
2021 is written MMXXI in Roman numerals.
Frequently asked questions
How do you write the year 2021 in Roman numerals?
The year 2021 is written MMXXI. Reading left to right that is M (1000) + M (1000) + X (10) + X (10) + I (1), added together to reach 2021.
Why does MMXXI start with MM?
MM is the numeral for 2000, and every year from 2000 to 2099 opens with it. The letters after it, XXI, carry the remaining 21.
Is MMXXI the same as 2021 on a clock?
No. Clock faces only run to XII, so a year never appears on a dial. MMXXI belongs on dates: credits, cornerstones, engravings and tattoos. A numeral read off a watch face is an hour between I and XII, not a year.
How is the year 2021 different from the number 2021?
They share the numeral MMXXI, but the year page focuses on dates, tattoos and dedications, while the number covers counting, chapters and general use. Same letters, different context.
Years people look up next
The decade anchors either side of 2021, its immediate neighbours, and the quarter and half century marks that anniversaries land on.