Your last name, measured against a real population
The U.S. Census Bureau published 162,253 surnames appearing at least 100 times in its 2010 surname tabulation. This lookup gives the recorded count, official rank and approximate “1 in” frequency for a spelling. It is a historical snapshot: it does not add births, subtract deaths or estimate migration since 2010.
The denominator is 294,979,229 people with recorded surnames, including the combined count for names below the published threshold. That is smaller than the entire 2010 Census population because not every record supplied a usable surname. For example, Smith appears 2,442,977 times, or about one in 121 surname records. See the surname method and original documentation for the exact calculation.
How the lookup treats spelling
Capitalization does not change the answer. Spaces, apostrophes and hyphens are removed before matching the published key: O’Brien and OBRIEN therefore reach the same table entry. This is a lookup convention, not a statement about the way you should write your name. Different letters are not silently substituted, and accented characters are not guessed into an unaccented spelling.
The Census applied editing rules before publication, including removing some suffixes and combining punctuation variants. A missing result is an uncertainty, not a personal distinction the tool can quantify. It would be misleading to turn every absent name into “one of a kind.” The released records do not provide that evidence.
A first name answers a different question
The first-name calculator compares baby-name records within one birth year. This surname calculator covers recorded residents in a single Census. The two populations differ, so the numbers should not be multiplied to estimate your full name’s rarity. The combined card can display both, with each source kept beside its own result. You can also add birthday rarity for a third independently labeled fact.
Your typed surname stays in the browser. The site downloads the public Census table, performs the lookup locally and exports an image only when you choose to save or share it.
Good questions
Which country does the surname result cover?
The United States, using surname records from the 2010 Census. It is not a worldwide estimate or a current population count.
What if my surname is not listed?
The public table lists surnames occurring at least 100 times. An absent spelling may have fewer records, be edited differently, or be missing from the source. The calculator cannot assign it a reliable count.
Does a shared surname mean we are related?
No. Surname frequency alone does not establish kinship, ancestry, ethnicity or the origin of an individual’s name.