Kaisei
#11,315 in 2025Boys' nameMeaning not yet documented
Kaisei has been given to 137 babies in the U.S. since 2005. In 2025 it ranked #11,315 of 13,926 boys’ names in use. Its peak year was 2007, with 10 recorded.
Babies named Kaisei, 2025
1 in 553,000
Kaisei over time, 1880–2025
Based on births in the U.S. Babies given the name each year. Hover the chart — or focus it and use the arrow keys — for any year. Gaps mean the name was given fewer than 5 times that year; these counts are unpublished.
How common is Kaisei?
Everything below is computed from the 2025 data — the most recent year available.
- Among all babies, 2025
- 1 in 553,000
- 6 of 3,315,165 births
- Among boys only
- 1 in 285,000
- <0.01% of boys
- Rank, 2025
- #11,315
- of 13,926 boys’ names in use
- Coin-flip room size
- 382,984 kids
- Even odds of a second one
Where Kaisei sits on the popularity scale
Chance at least one other child shares the name
If the other children were drawn at random from the 2025 national name distribution. Real classrooms cluster by region and community, so treat these as a floor, not a ceiling.
Put another way: gather 382,984 children born in 2025 and it's an even bet that one of them is another Kaisei. In a class of 30 the chance is Under 1%.
When Kaiseis were born
Half of everyone ever recorded as Kaisei was born before 2015 — so the typical Kaisei is around 10 today.
- Biggest decade
- 2010s
- 51.1% of all use
- Born in the last 25 years
- 100.0%
- A modern name
- Recorded since 1950
- 137
- People you could plausibly meet
2010s — 51.1% of all recorded uses (70).
Is Kaisei rising or falling?
Rank movement and count movement can disagree — the number of distinct names in use keeps growing, so a name holding a steady count still slides down the list. Both are shown.
- Rank vs 1 year ago
- −2,662
- Places dropped
- Rank vs 5 years ago
- New entry
- Not ranked then
- Rank vs 10 years ago
- −1,248
- Places dropped
- Births vs 10 years ago
- 0.86×
- Fewer babies than then
- Share of its own peak
- 60.0%
- Peak was 2007 (10)
- Years since peak
- 18
- Years
- Year-to-year steadiness
- Volatile
- 34.9% average annual change
Spellings of Kaisei
Kaisei is not the most common spelling — Kaiden is, with 43.7% against Kaisei's 0.11%.
Grouped by closeness of spelling (up to two letter changes), same sex, with a floor on all-time use. It catches Sophia/Sofia and Aiden/Ayden, and misses spellings that sound alike but look different, like Sean and Shawn.
Where Kaisei is used
Across 1910–2025, Kaisei was most concentrated in California — about 1 in — boys, against 1 in 3,486,540 across all states with data.
Most concentrated
- 1California1 in —
Shading is the share of that state's recorded boys given this name, not the raw count — otherwise the map would just show which states are biggest. Unshaded states have no published records for this period. U.S. birth records suppress state-year counts below 5; state counts therefore don't add up to the national total. Every state links to its full rankings. Kaisei has too little recent state data to map, so this covers all years from 1910.
Kaisei by the numbers
The raw record for each sex the name is used for.
Names similar to Kaisei
Matched on shared beginnings and endings, similar length, and comparable popularity.
Sibling names for Kaisei
Names from the same era and popularity tier — the two things that make a sibling set feel deliberate — skipping lookalike spellings and shared initials.