Surname Rarity Checker
See how rare your last name is, using the U.S. Census 2010 surname file.
Last names, by the numbers
Surnames follow their own math. This checker uses the U.S. Census Bureau 2010 surname file, which counts 266 million people across 162,253 last names. Type yours to see how many Americans share it and where it ranks nationally.
How rare is your last name, exactly
The tool turns the raw count into a plain "1 in X" figure. If a surname is held by 266,000 people out of 266 million, that is 1 in 1,000, so about one American in a thousand carries it. The smaller the group, the rarer the name, and the higher the "1 in X" number climbs. Alongside that ratio you get a national rank and a tier from Very Common down to Very Rare, so you can see at a glance where your last name sits.
The common end
Smith is the most common American surname, shared by more than 2.4 million people, followed by Johnson, Williams, Brown, and Jones. If your last name is one of these, expect a Very Common tier. Most family names are far less common, and plenty are carried by only a few hundred people.
The rare end
The Census only publishes surnames held by 100 or more people, to protect the privacy of the smallest families. That cutoff is itself a useful rarity line: a last name that is not on the list is carried by fewer than 100 Americans, which is about as rare as a surname gets. Names near the bottom of the published file, held by a few hundred people, already land in the Rare and Very Rare tiers.
What makes a last name rare
A few things push a surname toward the rare end:
- Recent or small-group immigration. Names that arrived with smaller waves have had less time and fewer families to spread.
- Spelling variants. One family name split across several spellings divides its count, so each spelling looks rarer than the sound of the name suggests.
- Regional roots. Some surnames stay concentrated in one area rather than spreading nationwide, which keeps the national count low.
What counts as a rare last name
Most people asking how rare their last name is are surprised by the answer, because surnames are far more spread out than first names.
Of the 162,253 surnames the Census publishes, only 5 land in the Very Common tier and another 216 in Common. Everything else is uncommon or rarer. Put differently: 69,896 published surnames, about 43 percent of them, are carried by fewer than 200 people in the entire country.
So if your last name is not Smith, Johnson, Williams, Brown, or Jones, it is already outside the top handful by a wide margin. The tiers here are set on the "1 in X" figure, not on rank, which keeps them honest:
| Tier | Roughly |
|---|---|
| Very Common | more than 1 in 200 people |
| Common | 1 in 200 to 1 in 2,000 |
| Uncommon | 1 in 2,000 to 1 in 20,000 |
| Rare | 1 in 20,000 to 1 in 200,000 |
| Very Rare | 1 in 200,000 to 1 in 2 million |
| Ultra Rare | rarer than 1 in 2 million |
The rarest last names
There is a floor built into the data. The Census only publishes surnames held by 100 or more people, so the rarest name it will show you sits at about 1 in 2.7 million Americans. Thousands of surnames tie at exactly that 100-person count.
That means there is no single "rarest last name in the world" this data can name, and any site claiming one is guessing. What the file can tell you honestly is whether your surname is above the line or below it. If your last name does not return a result here, fewer than 100 Americans carried it in 2010, which is rarer than anything on the published list.
Worldwide the question gets harder still, because most countries do not publish surname counts at all. A name that is vanishingly rare in the United States can be ordinary somewhere else.
Surname rarity is not the same as first-name rarity
The two run on different data and different logic, which is why the same person often gets very different answers.
First names come from 145 years of birth records, so the pool keeps refreshing as naming fashions turn over. Surnames are inherited, so they only change through marriage, migration, and family size. A first name can go from unheard-of to top ten in a decade. A surname essentially cannot.
That inheritance is also why surnames spread so thin. Every family line that dies out takes its name down with it, and no new babies revive it the way a fashionable first name gets revived.
First name or last name
The rarity idea is the same for both: how many people share it, turned into a "1 in X" figure and a tier. The data source is what changes. First names come from 145 years of birth records, while surnames come from the 2010 census snapshot of the living population. Curious about a given name instead? Try the first-name rarity checker on the home page, or see how rare your full name is.
Frequently asked questions
- How can I tell how rare my last name is?
- Type your surname into the checker above. It looks your name up in the U.S. Census 2010 surname file, shows how many Americans share it, and turns that into a "1 in X" figure, a national rank, and a rarity tier from Very Common to Very Rare.
- How rare is my last name?
- Type it into the checker above and you'll get an exact answer: a "1 in X" figure, a national rank out of 162,253 surnames, and a tier from Very Common to Very Rare, all from the U.S. Census 2010 surname file. "Last name" and "surname" mean the same thing here, so either way you ask it, this is the tool that answers it.
- How popular is my last name?
- This checker answers that the other way round from what you might expect: instead of a popularity rank alone, you get the "1 in X" figure and tier, which tell you the same thing. A last name in the Very Common tier is a popular one, shared by well over a million Americans. A name in the Very Rare tier is the opposite, held by only a few hundred people or fewer.
- What is the rarest last name?
- There is no single answer, because the Census only lists surnames held by 100 or more people. Any last name carried by fewer than 100 Americans is left off the public file entirely, so the true rarest names are the ones too uncommon to appear. Among listed names, the ones near the bottom are held by only a few hundred people each.
- What counts as a rare surname?
- As a rough guide, a last name shared by fewer than a few thousand Americans lands in the Rare or Very Rare tiers. Anything not on the Census list at all is carried by under 100 people, which is about as rare as a surname gets in the United States.
- Are different spellings of a surname counted separately?
- Yes. The Census counts each exact spelling on its own, so a family name split across two or three spellings has its total divided among them. That makes each individual spelling look rarer than the name would be if every variant were combined.
- Why is my last name not showing up?
- If nothing comes back, your surname is likely held by fewer than 100 people, which is the cutoff for the public Census file, or it may be spelled differently in the records. A missing name is itself a strong sign that the surname is very rare.
- Why is the surname data from 2010?
- The Census Bureau's most recent complete surname file comes from the 2010 count. It is the largest, most authoritative public source of last-name frequencies in the United States, so it remains the standard reference for surname rarity.
- How rare is my surname compared to other last names?
- Enter it above and the checker returns a tier, a national rank, and a plain 1 in X figure. For context, only 5 surnames in the whole Census file are Very Common and 216 are Common, so almost every surname lands in Uncommon or rarer.
- How common is your last name in the US?
- The Census 2010 surname file counts 265,667,228 people across 162,253 last names. The checker divides that population by the number of people carrying your name, which gives the 1 in X figure and the tier.
- What is the rarest last name in the world?
- No dataset can answer that honestly. The U.S. Census only publishes surnames held by 100 or more people, and most countries publish nothing at all. What this tool can tell you is whether your surname clears that 100-person line, which is about 1 in 2.7 million Americans.
- How many people have my last name?
- The checker shows the exact count from the 2010 Census alongside the rarity figure. Counts range from more than 2.4 million for Smith down to exactly 100 for the thousands of names sitting at the publication cutoff.
Last names people look up most
Each one has its own page with the full Census numbers, where the name comes from, and a card you can save.