21호 (isibil-ho) and 23호 (isipsam-ho): how Korean base numbering works, and why it stops so early
Korean base shades are numbered rather than named — 21 and 23 are the two most common, sitting roughly at light beige and natural medium beige, with letters such as N, W and C sometimes added for undertone. The ladder was built around a domestic range and historically stopped a step or two above where much of the world begins. Knowing what the numbers encode tells you within seconds whether a product has anything for you.
How the ladder works
The numbers run in steps of two: 13호, 17호, 19호, 21호, 23호, 25호 and occasionally beyond. Lower is lighter. The pair most brands actually stock is 21 and 23, which is why those two numbers appear on nearly every Korean base product you will see listed online. Undertone, where it is specified at all, arrives as a letter: N for neutral, W for warm, C for cool. So 21N and 23W are a lightness plus a lean, in a compact code that means nothing until you know the scale behind it.
Why it stops where it stops
Two shades cover a large share of a domestic customer base and keep inventory simple, and for years there was no commercial reason to go further. The consequence is a ladder topping out around 25호 that excludes an enormous proportion of the people now buying Korean cosmetics online. The numbering itself is not the villain — a numeric scale is arguably clearer than the invented names Western brands use, since it encodes depth directly and comparably within a range. The problem is where the ladder ends, and how few rungs sit anywhere near the bottom.
Mapping the numbers onto anything else
There is no reliable conversion between 호 (ho) numbers and another brand's shade names, and any chart claiming otherwise is guesswork dressed as data. Brands are not consistent with one another either: one house's 23 can sit noticeably deeper or warmer than another's. Treat the number as a within-brand ladder and nothing more. Knowing your match in one Korean brand is genuinely useful for buying more from that brand and only mildly useful elsewhere. Swatching stays the only method that works, ideally with two adjacent numbers laid side by side along the jaw.
Using the system if you sit outside it
If the deepest shade in a range is two or more steps lighter than you, walk away rather than hoping the coverage will sheer out — it will look grey, not sheer. If you sit at or just below the bottom rung, mixing is realistic: cushion refills and liquid bases blend readily with a drop of a deeper foundation or a pigment concentrate, and a warm cream bronzer can pull a slightly-too-light base into range around the perimeter. When choosing between two candidates, take the deeper one. Bases settle darker than they look going on.
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✍️ Written & reviewed by the KoreaPlus Editorial team — dermatologist-informed, cosmetic-science researched & source-cited. Last reviewed: 2026-08-23.
General educational information using cosmetic structure-function wording — not medical advice. Always patch-test new actives. © KoreaPlus.