Methodology

Every number on this site is a statistical estimate built from public government data. This page explains exactly where the data comes from, how the estimates are calculated, and where they can be wrong. If a figure on this site ever disagrees with your expectations, this page is the first place to look for why.

Data sources

• First names: Social Security Administration, "Baby Names from Social Security Card Applications — National Data." Annual counts of every name given to at least five babies of a sex, 1880–2024 (the March 2025 release). 104,819 distinct first names.
• Surnames: U.S. Census Bureau, "Frequently Occurring Surnames" genealogy file from the 2010 Census. 162,254 surnames borne by at least 100 people, with counts, ranks, and ancestry percentages.
• Population: U.S. population of 341.8 million (Census Bureau estimate), used to scale the 2010 surname counts to today and as the denominator for rarity figures.

From births to people alive today

Adding up all births since 1880 would overstate today's bearers, because many of those people have died. For each birth year we multiply the name's births by an approximate cohort survival probability to 2025, interpolated from SSA cohort life-table patterns (roughly: 99% survival at age 10, 93% at 50, 74% at 70, 51% at 80, 21% at 90, 3% at 100). The "living bearers" figure on every page is the sum of those adjusted cohorts. Age-group and decade breakdowns come from the same adjusted figures.

The full-name formula

Estimated bearers of an exact full name = (living bearers of the first name × today's bearers of the surname) ÷ 341.8 million. This assumes first names and surnames are statistically independent. That is a standard, reasonable approximation — and a known simplification: where a first name and surname come from the same cultural community, the true count is usually somewhat higher than the formula gives.

Rarity score and tiers

The rarity score converts "1 in X Americans" onto a 0–100 logarithmic scale (0 = the most common names in the country, 100 = a single bearer). Tiers: Very Common ≥ 1,000,000 living bearers; Common ≥ 500,000; Uncommon ≥ 100,000; Rare ≥ 10,000; Very Rare below that.

Known limits — read these

• The SSA does not publish a name given to fewer than 5 babies in a year, so extremely rare or newly coined names may show no result. That reflects the public record, not an error.
• SSA data counts births, not immigration. Living Americans born abroad are largely missing from first-name totals, so names common among immigrant communities are undercounted.
• Survival adjustment uses national average mortality; it does not vary by sex beyond the recorded counts, region, or era-specific events.
• Surname data is from the 2010 Census scaled by overall population growth; individual surnames grow at different rates.
• Different spellings (Sophia / Sofia) are separate names in the source data and are counted separately here.

Privacy

Lookups run in your browser against the published statistics. We do not store, log, or transmit the names you search. See the privacy policy.