Somaek ratio: where to stop pouring, and how strong it is
7.3%Example
1 soju shot + 150 ml beer = 7.3% ABV
(1×15.7 + 3×4.5) ÷ 4 = 7.3
φ — Euclid, Elements VI, def. 3
It marks the golden ratio of the height (whole : longer = longer : shorter). It has nothing to do with ABV.
Euclid, Elements Book VI, Definition 3 (D. E. Joyce, Clark University)
350 ml beer glass · soju line at 16.8% of the height · beer to 61.5%
15.7%: announced by Chamisul Fresh, Jinro (HiteJinro); Saero, Chum Churum (Lotte Chilsung) · 4.5%: Cass (OB Beer) · checked 2026-11-08
No drinking under 19 · Heavy drinking harms your health · Never drink and drive
How it's calculated, and the ratio table
ABV formula, line heights, the ABVs used, the gold line
ABV by ratio
| Ratio | Soju 15.7% | Soju 16% | Pour, 350 ml beer glass | Pour, 500 ml beer glass |
|---|---|---|---|---|
| Mild 1:4 | 6.7% | 6.8% | 50 + 200 ml | 50 + 200 ml |
| Usual 1:3 | 7.3% | 7.4% | 50 + 150 ml | 100 + 300 ml |
| 3:7 | 7.9% | 8.0% | 50 + 117 ml | 100 + 233 ml |
| Strong 1:2 | 8.2% | 8.3% | 100 + 200 ml | 150 + 300 ml |
| 1:1 | 10.1% | 10.3% | 150 + 150 ml | 200 + 200 ml |
How the ABV is calculated
Somaek ABV is the volume-weighted average of the soju and the beer. Mix a soju shots with b shots' worth of beer and you get (a × soju ABV + b × beer ABV) ÷ (a + b).
For the usual 1:3: (1×15.7 + 3×4.5) ÷ 4 = 7.3, so 7.3% ABV. The result is rounded half-up to one decimal, and the formula shows ≈ when the division doesn't end.
Volume contraction from mixing is left out, so the number is an approximation.
How the lines on the glass are drawn
One soju shot counts as 50 ml. We put in as many whole shots as fit without going over 90% of the beer glass (350 ml or 500 ml), then add beer for the ratio. The last 10% is room for foam.
Soju goes in first, so the lower solid line is the soju line and the dashed line above is where the beer stops. The drawn glass is 1.2 times wider at the top, so the same amount takes less height higher up.
Glass sizes, the 50 ml shot, the foam room and the glass shape are this tool's rules. The heights are exact for the drawn glass; real glasses differ a little.
Which soju and beer
Soju is counted at 15.7%: Chamisul Fresh (HiteJinro), announced 2026-06-02; Jinro (HiteJinro), announced 2026-02-12; Saero (Lotte Chilsung), announced 2026-01-21; Chum Churum (Lotte Chilsung), announced 2026-09-01. Older 16% bottles may still be around, so you can pick a 16% label too.
Beer is counted at 4.5%: Cass (OB Beer), announced 2025-05-31. With another beer the result changes with its label; put its number into the formula above.
Every ABV was checked in press reports of the makers' announcements. The makers' own pages did not load on the day we checked.
The gold line (φ)
The gold line at 61.8% of the height is the golden ratio (whole : longer = longer : shorter), from Euclid's Elements, Book VI, Definition 3. It stays put whatever you pick.
It has nothing to do with the ABV or the pour.
Health
The ABV here is not health advice. For healthy drinking limits, follow your health authority's guidance.
FAQ
- What is the somaek golden ratio?
There is no official one. Two common picks: 1:3 is 7.3% ABV and 3:7 is 7.9%. This tool shows five ratios, from a mild 1:4 to 1:1, with the ABV and the line on the glass.
- How do you calculate somaek ABV?
(soju shots × soju ABV + beer in shots × beer ABV) ÷ total shots. For 1:3: (1×15.7 + 3×4.5) ÷ 4 = 7.3, so 7.3%.
- How big is a soju shot?
Shot glasses vary. This tool counts one shot as 50 ml. That is this tool's rule, not an official standard.
- Did Chamisul's ABV change?
Yes. Chamisul Fresh (HiteJinro) announced a cut from 16% to 15.7% on 2026-06-02. So this tool uses 15.7% soju by default.
- How strong are Chum Churum, Saero and Jinro?
Chamisul Fresh (HiteJinro), announced 2026-06-02; Jinro (HiteJinro), announced 2026-02-12; Saero (Lotte Chilsung), announced 2026-01-21; Chum Churum (Lotte Chilsung), announced 2026-09-01. All are 15.7%. Older bottles may still be around, so check the label; if it says 16%, pick 'Soju 16%'.
- What if I use a different beer?
This tool uses 4.5% beer. If your label says something else, the result changes. The formula is shown, so you can put in your label's number.
- Is the ABV exact?
It's a volume-weighted approximation. The slight volume contraction when mixing is left out.
Sources
| Source | Date | What we checked |
|---|---|---|
| Kyunghyang Shinmun | 참이슬 후레쉬 15.7% | |
| Kyunghyang Shinmun | 진로 15.7% | |
| Bizwatch | 새로 15.7% | |
| CEO Score Daily | 처음처럼 15.7% | |
| Money Today | 카스 4.5% | |
| D. E. Joyce, Clark University | - | Euclid, Elements VI, def. 3 (the gold line) |
Checked
Illustration: AI-generated (Gemini), edited by plusbeauxjours