Korea's Lucky Numbers: 3, 7 and Tetraphobia

In Korean number culture the lucky numbers are 3 and 7, and the number people route around is 4. The reason four carries so much weight here is phonetic. Sino-Korean 사, the reading of 四, is identical to 사, the reading of 死, death. Korean has no tones, so nothing in speech separates them. Mandarin at least has sì set against sǐ. In Korean the two words are one sound, written the same way in hangul, told apart only by context or by writing out the hanja.

Three and seven do not work by wordplay at all, which is what makes them Korean rather than borrowed. Three comes out of the founding narrative recorded in the Samguk Yusa, where Hwanung descends from heaven with three ministers and three thousand followers, and out of the older preference for odd, yang numbers. Seven belongs to the Big Dipper. Korean folk religion venerates the Seven Stars as givers of long life, rain and children, and Korean Buddhist temples keep a chilseonggak, a Seven Stars hall built for that worship.

Avoidance of four is more thorough in Korea than in most places, and it is also completely unofficial. No law and no building standard requires anything. A lift panel showing F where the 4 should be is a decision made building by building, by a developer or a panel manufacturer, and towers on the same street print the 4 without comment. Nobody has counted how many do it either way. Ask a Korean under thirty and you will get a shrug, followed by a note that they still would not take room 404.

Lucky: 3, 7
Avoided: 4
Where: South and North Korea, and Korean communities abroad
Language: Korean, with Sino-Korean readings
Mechanism: 삼 (三) sam ≈ 삼세번 samsebeon
Sourced claims: 5 on this page

The wordplay behind it

What each number sounds like, stands for, or resolves to. This table is the whole explanation in one place.

Number	Written	Read as	Echoes	Meaning
3	삼 (三)	sam	삼세번 samsebeon	three tries, the full run	Lucky
4	사 (四)	sa	사 (死)	death	Avoided
4	넷	net	no homophone	the native Korean four, which echoes nothing at all	Both
7	칠 (七)	chil	칠성 chilseong	the Seven Stars of the Big Dipper	Lucky
8	팔 (八)	pal	no homophone	the Chinese eight-and-prosper pun does not survive into Korean	Both
9	구 (九)	gu	구 (久)	long-lasting; the pun exists in Korean but is rarely invoked	Both

The lucky numbers: 3, 7

One at a time, with the mechanism and one place it actually shows up.

3 — the number of a complete attempt

Three is the odd number Korea leans on hardest, and it does the work in ordinary speech rather than in ritual. 삼세번 samsebeon, three tries, is the everyday phrase for giving something a fair go, and 삼세판 samsepan is the best of three that settles a game or an argument. The founding narrative in the Samguk Yusa is built on it: Hwanung comes down from heaven with three ministers, of wind, rain and cloud, and three thousand followers. The standard Korean funeral, samil-jang, runs three days from the death to the burial.

7 — the Seven Stars

Seven in Korea is astronomical before it is anything else. 칠성 chilseong is the Big Dipper, and in Korean folk belief the Seven Stars deity governs lifespan, rain and childbirth. Korean Buddhist temples began building chilseonggak halls for that worship in numbers after the Imjin War, a hall type Korean Buddhism developed for itself. The seventh night of the seventh lunar month is Chilseok, when the weaver Jiknyeo and the herdsman Gyeonu cross the Milky Way on a bridge of magpies. Household rites for the Seven Stars were traditionally led by the oldest woman in the family.

The numbers to avoid: 4

Same treatment. Where an avoidance has a documented cost, it is named.

4 — a homophone with nothing to separate it

Korean borrowed the number four from Chinese as 사 and the word for death as 사, and unlike Mandarin it has no tone to hold the two apart. What follows is one of the most thorough number avoidances anywhere. Lift panels label the fourth floor F, hospitals and funeral halls skip it outright, and flats numbered 404 sell more slowly than their neighbours. Korail's 4400-class diesel locomotives run from 4401 to 4460 with no 4444 among them. Korean also kept a native word for four, 넷, and that one carries nothing.

Where you actually meet it

Lifts are the signature. A Korean panel will often read B1, 1, 2, 3, F, 5, with the letter doing exactly the job the digit would have done. Nothing requires it: there is no clause in the building code, no standard from any ministry, and no survey saying how common the substitution is. The choice belongs to whoever specified the buttons. Other towers on the same block print a plain 4 and nobody treats that as a provocation, which is roughly the state of the belief in general.

Hospitals take it further than housing does, and funeral halls further still, because that is where the word sits closest to the surface. Room numbers containing a four get skipped, and so do apartment units like 404, which estate agents will tell you shift more slowly than the flats above and below them. The habit reaches into transport as well: the diesel locomotive class Korail numbered upward from 4401 was built without a 4444 in it.

The lucky side is quieter and lives on a calendar rather than a lift panel. Chilseok, the seventh night of the seventh lunar month, is still marked with wheat pancakes and a wish for the right weather, and rites for the Seven Stars are held in the temple halls built for them. Three runs through ordinary language so completely that most Koreans would not file samsebeon under superstition at all, only under the number of goes a thing deserves.

Checkable claims

Each of these is a documented fact rather than a general impression, with the source named.

The Samguk Yusa, compiled around 1281 by the monk Iryeon, records that Hwanung descended from heaven with three ministers, of wind, rain and cloud, and three thousand followers.

Samguk Yusa, c. 1281

In Korean, 사 is the reading of both 四, four, and 死, death. Korean has no tones, so the two are identical in speech and identical in hangul, separated only by context or by writing the hanja.

National Institute of Korean Language, Standard Korean Language Dictionary

Chilseok falls on the seventh day of the seventh month of the Korean lunisolar calendar. In 2025 that was 29 August.

Korean lunisolar calendar

Korean Buddhist temples keep a chilseonggak, a hall dedicated to the Seven Stars of the Big Dipper. The halls began to be built widely after the Imjin War of 1592 to 1598 and the building type is particular to Korean Buddhism.

Korean Buddhist temple architecture after the Imjin War

No South Korean law, building code or national standard governs whether a fourth floor is numbered 4 or labelled F. The substitution is decided building by building, and no official count exists of how many buildings use it.

South Korean building regulations

What it changes

A flat numbered 404 is the same flat it would be numbered 405, and the letter F on a lift button changes the button and nothing else. What sits underneath is a real feature of the language: two words Korean cannot keep apart in speech, and a culture that chose to route around one of them rather than argue with it. Knowing why the button says F is worth something. Reading a fortune into it is not.

That is the line this site holds everywhere: a tradition is worth knowing, and no number has ever moved a probability. If you want a set of numbers to play with anyway, the daily generator makes one from your birth date and tells you exactly how.

Korean lucky numbers — frequently asked

Because 사, four, is the same syllable as 사, death. F stands for four without anyone having to say it. No rule requires the substitution and plenty of buildings skip it.

No, and this is where Korea parts company with its neighbour. The Chinese luck in those numbers rests on puns that only work in Chinese: 八 bā against 發 fā, 六 liù against the sense of going smoothly. Read in Korean they become 팔, 육 and 구 and the puns simply vanish. Nine has a faint claim through 久, long-lasting, but Koreans rarely bother with it.

Odd numbers were treated as yang and auspicious, and three had a head start in the founding story. It survives in plain language rather than in ritual: samsebeon, three tries, and samsepan, best of three.

There is an older Korean seven with nothing Western about it. 칠성, the Seven Stars of the Big Dipper, is a folk deity of lifespan and childbirth with dedicated halls in Buddhist temples, and Chilseok is a festival on the seventh night of the seventh month.

Harder to answer than it sounds, because nobody counts. New buildings still go up with F on the panel and new buildings still go up with a 4.

The other traditions

Same questions, different language and different answers.

ChineseLucky 6 8 9 · avoid 4 GermanLucky 3 4 7 · avoid 13 IndianLucky 108 9 7 · avoid 8 ItalianLucky 3 7 13 · avoid 17 JapaneseLucky 3 7 8 · avoid 4 9 JewishLucky 18 7 13 · avoid 2 RussianLucky 3 7 · avoid 2 13 ThaiLucky 9 5 · avoid 6 4 WesternLucky 7 3 12 · avoid 13

More ways in

Unlucky numbers13, 4, 17, 666 and 39, and the documented history of each.Open →Chinese zodiacTwelve animals, their lucky numbers, and the lunar new year rule.Open →NumerologyThe western system: one number from a birth date or a name.Open →

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