Kai vs Leo
Kai and Leocompared on official birth-registration statistics and Namewise's recorded data. This page states what each name's record shows — it never picks a winner or scores one name against the other.
Head to head
Ranks are only compared within one published list and one year. Two ranks from different years, from a boys' and a girls' list, or from different registrars are not comparable, so they are not placed side by side.
England and Wales · Boys
In 2024, Kai was ranked #72 and Leo #5 among boys in England and Wales.
New South Wales, Australia · Boys
In 2025, Kai was ranked #23 and Leo #5 among boys in New South Wales, Australia.
Scotland · Boys
In 2024, Kai was ranked #56 and Leo #5 among boys in Scotland.
Republic of Ireland · Boys
In 2025, Kai was ranked #34 and Leo #10 among boys in Republic of Ireland.
Northern Ireland · Boys
In 2024, Kai was ranked #69 and Leo #12 among boys in Northern Ireland.
Norway · Boys
In 2025, Kai was ranked #282 and Leo #28 among boys in Norway.
England and Wales · Girls
In 2020, Kai was ranked #3117 and Leo #5493 among girls in England and Wales.
Kai and Leo over time
Kai and Leo appear together in 5 published lists, across 158 years of shared records. Leo held the stronger position in more years in 4 of them, Kai in 1.
The order between them changed and held in 3 of those lists — a change in that published list, never a claim that one name displaced the other.
Kai reached its own highest recorded position earlier in 4 of those lists, Leo in 1. Each position is a place inside its own list, so this compares when they peaked and never how high.
Counted list by list. Two names in the same published list are measured on the same scale in the same year, so those comparisons are real — but positions from different lists are not, so nothing here is combined into an overall standing.
How this pair is related
The relationship kinds these two qualify for, each under its own stated rule. Every one is drawn from a list they both appear in.
- One moved ahead of the other
In 2004, Leo moved ahead of Kai in England and Wales · Boys — #56 and #77 the year before became #62 and #57.
- Repeatedly exchanged positions
Kai and Leo changed places 6 times in Northern Ireland · Boys between 1998 and 2024, ending at #69 and #12.
- Closest over the longest run
Across 29 shared years in England and Wales · Boys, Kai and Leo averaged 55.3 places apart, ending at #72 and #5.
- Longest-running competitions
Kai and Leo were both ranked in Norway · Boys for 57 years, from 1947 to 2025, ending at #282 and #28.
- Peaked in the same years
Both reached their highest recorded position in New South Wales, Australia · Boys within 2 years — Kai #20 in 2023, Leo #3 in 2022.
List by list
Norway · Boys57 shared years, 1947–2025
Kai held the stronger position in 30 of those years, Leo in 27.
Highest recorded here: Kai #57 in 1976, Leo #28 in 2025.
The order changed in 2000: Leo moved ahead. In 1999 they stood at #270 and #281; by 2000 that had become #346 and #192.
Most recent shared year, 2025: Kai #282, Leo #28.
England and Wales · Boys29 shared years, 1996–2024
Kai held the stronger position in 8 of those years, Leo in 21.
Highest recorded here: Kai #56 in 2003, Leo #5 in 2022.
The order changed in 2004: Leo moved ahead. In 2003 they stood at #56 and #77; by 2004 that had become #62 and #57.
Most recent shared year, 2024: Kai #72, Leo #5.
Republic of Ireland · Boys28 shared years, 1997–2025
Kai held the stronger position in 0 of those years, Leo in 28.
Highest recorded here: Kai #30 in 2024, Leo #10 in 2025.
The order between them never changed and held in this list.
Most recent shared year, 2025: Kai #34, Leo #10.
Northern Ireland · Boys27 shared years, 1998–2024
Kai held the stronger position in 4 of those years, Leo in 23.
Highest recorded here: Kai #52 in 2021, Leo #6 in 2023.
The order between them never changed and held in this list.
Most recent shared year, 2024: Kai #69, Leo #12.
New South Wales, Australia · Boys17 shared years, 2009–2025
Kai held the stronger position in 2 of those years, Leo in 15.
Highest recorded here: Kai #20 in 2023, Leo #3 in 2022.
The order changed in 2011: Leo moved ahead. In 2010 they stood at #70 and #82; by 2011 that had become #80 and #65.
Most recent shared year, 2025: Kai #23, Leo #5.
Two names moving past each other in a ranking is a fact about the ranking. Namewise does not claim one name displaced the other, that families chose between them, or that either influenced the other — none of that is in this data.
Side by side
| Field | Kai | Leo |
|---|---|---|
| Record type | Official statistical record (evidence-only) | Editorially researched profile |
| Gender usage | male | male |
| Meaning | Not yet recorded | Lion. |
| Origin | Not yet recorded | Latin |
| Pronunciation | Not yet recorded | /ˈliːoʊ/ |
| Syllables | 1 | 1 |
| Common variants / nicknames | Not yet recorded | Not yet recorded |
| Recorded regional usage | AU-NSW, GB-ENW, GB-NIR, GB-SCT, IE, NO | AU-NSW, GB-ENW, GB-NIR, GB-SCT, IE, NO, NZ |
| Most recent popularity observation | New South Wales, Australia · Boys #23 (2025) | New South Wales, Australia · Boys #5 (2025) |
| Pronunciation clarity (demonstration score) | Not yet recorded | 90/100 |
| Spelling simplicity (demonstration score) | 95/100 | 95/100 |
| International familiarity (demonstration score) | 100/100 | 100/100 |
| Data Confidence | medium | medium |
What the data shows
- Leo has a recorded origin (Latin); Kai does not have one recorded yet.
- Kai and Leo both have 1 syllable.
- A meaning is recorded for Leo; Kai doesn't have one written yet.
- Both names have recorded usage in AU-NSW, GB-ENW, GB-NIR, GB-SCT, IE, NO.
How each name got here
Kai
Popularity journey
First recorded1945
First recorded at #76 among boys in Norway in 1945 — the earliest year that source publishes this name, not necessarily the earliest it was used.
Norway · Boys
Highest recorded2002–2025
Highest recorded position: #20 among boys in New South Wales, Australia, in 2023 (recorded 2002–2025).
New South Wales, Australia · Boys
Most recent2025
Most recently recorded at #23 among boys in New South Wales, Australia, in 2025.
New South Wales, Australia · Boys
Leo
Popularity journey
First recorded1947
First recorded at #303 among boys in Norway in 1947 — the earliest year that source publishes this name, not necessarily the earliest it was used.
Norway · Boys
Highest recorded2009–2025
Highest recorded position: #3 among boys in New South Wales, Australia, in 2022 (recorded 2009–2025).
New South Wales, Australia · Boys
Most recent2025
Most recently recorded at #5 among boys in New South Wales, Australia, in 2025.
New South Wales, Australia · Boys