Ordinal Number Calculator
An ordinal number describes the position or rank of an item in a sequence. This calculator converts any whole number into its ordinal form. For example, 1 becomes 1st, 22 becomes 22nd, and 103 becomes 103rd. Ordinal numbers are essential in English for describing order, ranking, and sequence. They are used in dates ('the 4th of July'), competitions ('she came in 2nd place'), and general descriptions of position ('the 5th chapter', 'the 10th anniversary'). English ordinal number formation follows specific rules, with some exceptions for numbers 11, 12, and 13. This calculator applies those rules automatically, so you can quickly find the correct ordinal form of any number without needing to remember the rules.
Ordinal numeral
Ordinal word
Ordinal number rules
| Rule | Pattern | Examples |
|---|---|---|
| Numbers ending in 1 (except 11) | -st | 1st, 21st, 31st, 101st, 121st |
| Numbers ending in 2 (except 12) | -nd | 2nd, 22nd, 32nd, 102nd, 122nd |
| Numbers ending in 3 (except 13) | -rd | 3rd, 23rd, 33rd, 103rd, 123rd |
| All other numbers (including 11, 12, 13) | -th | 4th, 5th, 11th, 12th, 13th, 20th, 100th |
Ordinal numbers: frequently asked questions
What is an ordinal number?
An ordinal number indicates the position or order of an item in a sequence. Unlike cardinal numbers (1, 2, 3), ordinals describe rank or sequence: first, second, third, fourth. Ordinals are written as 1st, 2nd, 3rd, 4th, 11th, 21st, 102nd, etc.
What are the ordinal rules in English?
Numbers ending in 1 use -st (except 11), like 21st, 31st. Numbers ending in 2 use -nd (except 12), like 22nd, 32nd. Numbers ending in 3 use -rd (except 13), like 23rd, 33rd. All other numbers use -th. The exceptions are 11th, 12th, and 13th.
How are ordinals used?
Ordinals are used when describing sequences or positions: 'She finished in 3rd place', 'The meeting is on the 15th of June', 'This is the 1st time we have met'. They are common in dates, rankings, and descriptions of order.
What is the difference between ordinal and cardinal numbers?
Cardinal numbers count quantity: 1, 2, 3, 100. Ordinal numbers describe position or order: 1st, 2nd, 3rd, 100th. Cardinal numbers answer 'how many', while ordinals answer 'which one' in a sequence.
Why are 11, 12, and 13 special?
These numbers break the usual pattern. They end in 1, 2, and 3, but do not use the typical -st, -nd, or -rd endings. Instead, they all use -th: eleventh, twelfth, thirteenth. This is a historical quirk of English inherited from Germanic number patterns.
Methodology
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.