How the HONMONO Score Works
Every one of the 1,706 open facilities in our database carries a HONMONO Score. It is our own number, not a Google rating — it is built from six categories, and this page explains what each one measures and how to read the result.
Figures read from our database 2026-09-14 06:26 JST — rankings and counts are calculated at this moment, not stored.
Newest facility info in this set 2026-08-15 / Source: publicly available Google Maps listings. The HONMONO Score is calculated by this site from that data.
What the numbers look like
The score is not a five-star scale. Across the whole database the average sits near the middle and high scores are genuinely uncommon, so a facility in the 60s is already unusual.
- Facilities scored1,706
- Average score47.9
- Highest score82
- Scoring 70 or above51 (3.0%)
- Scoring 60 or above261 (15.3%)
- Scoring 50 or above597 (35.0%)
The six categories
All six categories share the same ceiling of 17 points. The rules below are the implementation, not a paraphrase — the full formula, our weighting and the current distribution are on the score definition page. What matters in practice is where a facility sits relative to everything else.
Cold Bathaverage 11.7 · highest observed 15
Google rating 3.0 or higher: rating × 2.5, rounded (capped at 10; below 3.0 it is 0). Review count 500 or more +4, 200 or more +3, 50 or more +2, 10 or more +1 (0 on current data, where the maximum is 5). Facility facts: cold bath 14°C or colder +4, 17°C +3, 20°C +2, warmer than that +1. Aufguss performers: 10 or more +2, 5 or more +1. Floor: Google rating 3.5 or higher: at least 6; otherwise no floor (0).
Heat Qualityaverage 7.2 · highest observed 17
10 terms (熱波, アウフグース, ロウリュイベント, 熱波師, セルフロウリュ, オートロウリュ, 薪サウナ, バレルサウナ, ハーバルサウナ, 薬草サウナ): +2 each, capped at 8. Facility name contains サウナ / SAUNA: +3. Facility facts: sauna room 90°C or hotter +3, 80°C +2, 70°C +1. Facility facts: löyly type is aufguss +3, any other löyly +1. Aufguss performers: 10 or more +7, 5 or more +4, 2 or more +2; a named leader +1. Floor: If any review or summary exists: at least 6 with a Google rating of 3.5 or higher, otherwise at least 3 (0 if neither exists).
Outdoor Airaverage 5.8 · highest observed 11
Review count 501 or more: 8; 301+: 7; 101+: 6; 51+: 5; 21+: 4; 6+: 3; 1+: 2 (at most 2 on current data, where the maximum is 5). 5 terms (外気浴, 露天, ととのい椅子, デッキチェア, インフィニティチェア): +2 each, capped at 4. Facility facts: outdoor-air area confirmed +5. Aufguss performers: 5 or more +3, 2 or more +1. Floor: If any review or summary exists: at least 4 with a Google rating of 3.5 or higher, otherwise at least 2 (0 if neither exists).
Cleanlinessaverage 8.8 · highest observed 16
Official website exists: +3. Review count 10 or more +2, and 100 or more with a Google rating of 3.5 or higher +2 (0 on current data, where the maximum is 5). Google rating 4.5 or higher +5, 4.0 or higher +3, 3.5 or higher +1. 5 terms (清潔, きれい, 綺麗, 清掃, 掃除): +1.5 each, rounded down, capped at 3. Aufguss performers: 10 or more +4, 5 or more +3, 2 or more +1. Floor: If any review or summary exists: at least 5 with a Google rating of 3.5 or higher, otherwise at least 3 (0 if neither exists).
Sauna Focusaverage 7.8 · highest observed 17
5 terms (水風呂, 岩盤浴, 炭酸泉, 休憩, ととのい): +2 each, capped at 6. Facility name contains サウナ / SAUNA: +3. Facility facts: +1 per filled item out of 4 (sauna temperature, cold-bath temperature, outdoor air, löyly type), capped at 3. Aufguss performers: 10 or more +5, 5 or more +4, 2 or more +2; a named leader +2. Floor: If any review or summary exists: at least 7 with a Google rating of 3.5 or higher, otherwise at least 4 (0 if neither exists).
Aroma & Löylyaverage 6.6 · highest observed 13
10 terms (アロマ, ハーブ, ハーバル, ヴィヒタ, 白樺, ロウリュ, セルフロウリュ, 薬草, ウィスキング, アロマロウリュ): +2 each, capped at 8. Facility facts: löyly type aroma 5, aufguss 4, self / auto 3, any other löyly 2. Aufguss performers: 10 or more +5, 5 or more +4, 2 or more +2; a named leader +1. Floor: If any review or summary exists: at least 6 with a Google rating of 3.5 or higher, otherwise at least 3 (0 if neither exists).
What separates the top facilities
Comparing the 50 highest-scoring facilities against the whole database shows which categories actually pull a score upward. The gap is largest where the top places are doing something most facilities do not.
| Category | All | Top 50 | Gap |
|---|---|---|---|
| Heat Quality | 7.2 | 12.5 | +5.2 |
| Cleanliness | 8.8 | 13.9 | +5.0 |
| Aroma & Löyly | 6.6 | 10.8 | +4.2 |
| Outdoor Air | 5.8 | 9.9 | +4.1 |
| Sauna Focus | 7.8 | 11.9 | +4.0 |
| Cold Bath | 11.7 | 14.9 | +3.2 |
Read this as a shopping guide: if one category matters to you more than the others, the score breakdown on each facility page tells you whether that is where the place puts its effort.
A note on what the score is not
The HONMONO Score is not a health rating and not a measure of 「ととのう」 (totonou), the word regulars use for how they feel after the hot–cold–rest cycle. That is a subjective experience; we do not measure it and we make no claims about health effects.
It is also separate from the Google rating shown on each page. The two often disagree — a facility can be well liked and still be a small hot room attached to something else.
The highest-scoring facilities
These are the top 8 by score among facilities that have an English summary.
Find a sauna
Every listing carries an English summary written from what visitors actually report.