Thai Numbers 1–100 — the Whole System in Ten Words (Audio)

Ten words buy you a hundred

Here's the best news you'll get all week: Thai numbers are almost perfectly regular. Learn ten words, add two small rules, and you can build every number to 99 — no "eleven, twelve" nonsense, no French-style "four-twenties-nineteen" arithmetic. Thai just says what the number is.

The ten, with real course audio — listen to each one, because a couple of the tones are non-negotiable:

• 1 — หนึ่ง (nùeng) ▶
• 2 — สอง (sǎwng) ▶
• 3 — สาม (sǎam) ▶
• 4 — สี่ (sìi) ▶
• 5 — ห้า (hâa) ▶
• 6 — หก (hòk) ▶
• 7 — เจ็ด (jèt) ▶
• 8 — แปด (bpàet) ▶
• 9 — เก้า (gâo) ▶
• 10 — สิบ (sìp) ▶

If the little marks over the vowels are new to you: those are tones, they're not optional, and they're friendlier than they look — here's how the whole tone system works.

The two rules (and the two traps)

Numbers 11–99 are built like maths: tens word + units word. สามสิบ (sǎam-sìp) is "three-ten" — 30. สามสิบสอง (sǎam-sìp-sǎwng) is "three-ten-two" — 32. That's the whole machine. Except:

Trap one: the 1 in 11, 21, 31… changes its name. At the end of a compound, หนึ่ง (nùeng) becomes เอ็ด (èt). So 11 is สิบเอ็ด (sìp-èt), never สิบหนึ่ง (sìp-nùeng) — and 21 is ยี่สิบเอ็ด (yîi-sìp-èt). Say สิบหนึ่ง at a market and you'll be understood, gently, the way "one-teen" would be understood in English.

Trap two: the 2 in 20 changes its name too. Twenty is ยี่สิบ (yîi-sìp) — not สองสิบ (sǎwng-sìp). It's the only ten that does this; 30 through 90 are perfectly regular (สามสิบ sǎam-sìp, สี่สิบ sìi-sìp… เก้าสิบ gâo-sìp).

Worked examples, built from the ten words above: 15 = สิบห้า (sìp-hâa) · 44 = สี่สิบสี่ (sìi-sìp-sìi) · 55 = ห้าสิบห้า (hâa-sìp-hâa) · 99 = เก้าสิบเก้า (gâo-sìp-gâo). And 100 has its own word — ร้อย (ráwy) ▶ — so 100 is หนึ่งร้อย (nùeng-ráwy), and the system keeps climbing: พัน (phan) is 1,000.

Numbers in the wild: prices

You'll use Thai numbers mostly with money — the currency is บาท (bàat) ▶ — and the phrase that starts every transaction is เท่าไหร่ (thâo-rài) ▶ — "how much?" The answer comes back as a number + บาท, which is exactly why the tens system is worth drilling before your trip: ห้าสิบบาท (hâa-sìp bàat, 50 baht) and ห้าร้อยบาท (hâa-ráwy bàat, 500 baht) are one syllable apart and ten times the price.

Three companions that make prices painless: ครึ่ง (khrûeng) — half; ทั้งหมด (tháng-mòt) — "all of it / in total," for when you're buying several things; and at any market where bargaining is normal, ลดหน่อยได้ไหม (lót nàwy dâai mǎi) ▶ — "can you lower it a little?" — asked with a smile. When change comes back, that's เงินทอน (ngoen-thawn).

Why Thais laugh in fives

Five is ห้า (hâa). Type 555 and you've typed "hâa hâa hâa" — which is why Thai internet comments are full of 555, 5555, and for something truly funny, 55555+. It's "hahaha," in base ten. You now get the joke that greets every foreigner's first Thai group chat.

(Thai also has its own digits — ๑ ๒ ๓ ๔ ๕ — which you'll meet on temple signs and, famously, on dual-priced entry tickets. Arabic numerals dominate daily life, but if you want to read the Thai ones, the script has a whole guide, and PaiThai's reading track teaches the numerals alongside real street-sign words.)

Drill them where it counts

Numbers are pure recall speed — you don't "know" สี่สิบห้า (sìi-sìp-hâa, 45) until it surfaces in under a second with a vendor waiting. PaiThai drills numbers with audio from the first units, inside real price-and-shopping conversations rather than flashcards. The first three conversation units are free, in your browser, no account: app.paithai.app. Bring เท่าไหร่ — you'll need it by day two of your trip.