The most common zodiac sign, and the rarest

• Most common

  Leo · 8.96%

  5,572,147 estimated births

• Rarest

  Capricorn · 7.63%

  4,747,380 estimated births

• Born on a cusp day

  3.30%

  180 of 5,479 days had a sign change

• Longest sign

  Cancer · 31.45 days

  shortest: Capricorn, 29.44 days

Share of births by Sun sign

US births, 2000–2014 (62,187,024 in total), assigned to Sun signs using the exact sign-change instant of each year. The dashed line marks 8.33%, the share every sign would have if all were equal.

All 12 signs, most to least common

* Index 100 = the yearly average: above 100, the sign gets more births per day than its length alone would give it. The 1994–2003 column is a cross-check from a second source (CDC/NCHS): it gives the same most and least common sign.

Why are some signs more common than others?

Signs aren't the same length. Earth moves slowest near aphelion in early July, so the Sun takes longer to cross the northern-summer signs. From 1980 to 2030, Cancer lasted 31.45 days on average and Capricorn only 29.44: almost two days' difference before a single birth is counted.

Births aren't spread evenly over the year. In this data, 7 of the 10 busiest birth dates fall in September, and holidays see fewer scheduled deliveries. Virgo has the most births per day of any sign (index 105.6).

Leo comes out on top because it has both: it's long (31.30 days, 0.39 more than Virgo) and it falls in high-birth months. Capricorn is short and contains December 25, January 1, December 24, the three dates with the fewest births.

How many people are born on a cusp?

3.30% of births (2,052,314 of 62,187,024) fell on a date when the Sun changed sign: 180 of 5,479 days, twelve a year. For those people the date isn't enough; the sign depends on the time and place of birth.

Being "on the cusp" doesn't mean being between two signs: the Sun crosses the boundary at one exact minute. The cusp pages give that minute for every year from 1980 to 2030.

The most and least common birthdays

Average US births per calendar date, 2000–2014 (daily mean: 11,350). February 29 is averaged over leap years only.

September 12 tops the list. The quietest dates are US holidays, when fewer C-sections and inductions are scheduled; other countries can show a different pattern.

Methodology & sources

Sign dates. The instant the Sun entered each sign, 1980–2030, computed with astronomy-engine (apparent ecliptic longitude, tropical zodiac). It's the same computation as the cusp dataset and every chart on this site.

Assignment. Each birth date is treated as a local day at UTC-6 (roughly the population-weighted US time zone). If the Sun changed sign during that day, its births are split between the two signs by the hours on each side of the crossing, assuming births are spread evenly through the day.

Sensitivity. Re-run at UTC−5, UTC−8 and UTC+0, no share moves more than 0.006 percentage points and the ranking doesn't change.

Reproducible. A script in the site's repository reads the source files pinned to an exact version, checks their SHA-256, and recomputes every number on this page; tests check that the shares sum to 100%.

Limits

• These are US estimates. Other countries, especially in the southern hemisphere, have different birth seasons, so the order can change; sign lengths are the same everywhere.
• Only births from 2000–2014 count (and 1994–2003 as a cross-check), not the living population today.
• Births aren't really uniform through the day (scheduled deliveries cluster in the morning); this only affects cusp days.
• Tropical zodiac, as used in Western astrology. Not the constellations, not the sidereal zodiac.
• A sign being common says nothing about anyone's personality: it's a matter of the calendar and of when babies are born.

Sources

1. FiveThirtyEight, "U.S. Births", file US_births_2000-2014_SSA.csv (US Social Security Administration data). GitHub, license CC BY 4.0, retrieved 2026-10-11.
2. FiveThirtyEight, "U.S. Births", file US_births_1994-2003_CDC_NCHS.csv (CDC National Center for Health Statistics data). Same license, retrieved 2026-10-11.
3. Solar ingresses 1980–2030: My Chart Check dataset (CC0), computed with astronomy-engine (MIT).

The numbers come from the script described above. The text was drafted with AI assistance and checked against that data.

Cite this data