Ordinal Number Converter
Ordinal Number Converter
Ordinal numbers describe position in a sequence — 1st, 2nd, 3rd — rather than quantity, and English's ending rules have a well-known exception that trips people up: numbers ending in 11, 12, or 13 always take "th", even though their last digit would otherwise suggest "st", "nd", or "rd". Enter any whole number here and this calculator converts it to its correct ordinal form automatically, handling that exception along with the standard pattern for every other number.
- Ordinal numbers indicate position or order (1st, 2nd, 3rd, 4th…), while cardinal numbers indicate quantity (one, two, three, four…).
- English ordinal endings mostly follow the last digit: 1 → st, 2 → nd, 3 → rd, and everything else → th — except numbers ending in 11, 12, or 13, which always use "th" (11th, 12th, 13th, not 11st).
- This exception is why 21st and 22nd look different from 11th and 12th despite similar-looking last digits — 21 and 22 fall outside the 11-13 exception range.
Why is 11 written as "11th" instead of "11st"?
Numbers ending in 11, 12, or 13 are a standard exception in English and always take the "th" ending, regardless of their last digit.
What is 21 in ordinal form?
21st — since it ends in 1 (and doesn't fall in the 11-13 exception range), it takes the "st" ending.
Ordinal Number Converter
Ordinal numbers describe position in a sequence — 1st, 2nd, 3rd — rather than quantity, and English's ending rules have a well-known exception that trips people up: numbers ending in 11, 12, or 13 always take "th", even though their last digit would otherwise suggest "st", "nd", or "rd". Enter any whole number here and this calculator converts it to its correct ordinal form automatically, handling that exception along with the standard pattern for every other number.
- Ordinal numbers indicate position or order (1st, 2nd, 3rd, 4th…), while cardinal numbers indicate quantity (one, two, three, four…).
- English ordinal endings mostly follow the last digit: 1 → st, 2 → nd, 3 → rd, and everything else → th — except numbers ending in 11, 12, or 13, which always use "th" (11th, 12th, 13th, not 11st).
- This exception is why 21st and 22nd look different from 11th and 12th despite similar-looking last digits — 21 and 22 fall outside the 11-13 exception range.
Why is 11 written as "11th" instead of "11st"?
Numbers ending in 11, 12, or 13 are a standard exception in English and always take the "th" ending, regardless of their last digit.
What is 21 in ordinal form?
21st — since it ends in 1 (and doesn't fall in the 11-13 exception range), it takes the "st" ending.