Learn Spanish Numbers
This page teaches the key patterns for Spanish number words — with lots of examples (and the common traps: cien vs. ciento, accents, veintiún, un millón).
0–29: building blocks
It's best to memorize 0–15 (cero … quince). Then the patterns kick in:
- 16–19: dieci- + number → dieciséis, diecisiete, dieciocho, diecinueve
- 20: veinte
- 21–29: veinti- + number → veintiuno, veintidós, veintitrés, …
Quick check: 18, 22, 29?
18 dieciocho · 22 veintidós · 29 veintinueve
30–99: tens + "y" + ones
From 30 onward the standard pattern is: tens + (y + ones) when the ones digit is not zero.
- 30 = treinta
- 31 = treinta y uno
- 42 = cuarenta y dos
- 98 = noventa y ocho
100–999: cien vs. ciento & hundreds
- 100 = cien
- 101–199 = ciento + … (e.g. 115 = ciento quince)
- 200–900: doscientos, trescientos, cuatrocientos, …
Frequently-missed irregular hundreds: quinientos (500), setecientos (700), novecientos (900).
Quick check: 100, 115, 500, 742?
100 cien · 115 ciento quince · 500 quinientos · 742 setecientos cuarenta y dos
Thousands
- 1000 = mil (not "un mil")
- 2000 = dos mil
- 4321 = cuatro mil trescientos veintiuno
Before mil, uno → un (apocope): 21,000 = veintiún mil, 31,000 = treinta y un mil. (With a feminine noun you may also see "treinta y una mil personas", but for "numbers alone", "treinta y un mil" is the default.)
Millions & large numbers
- 1,000,000 = un millón
- 2,000,000 = dos millones
- 1,234,567 = un millón doscientos treinta y cuatro mil quinientos sesenta y siete
- 1,000,000,000 = mil millones (also: "un millardo")
- 1,000,000,000,000 = un billón (Spanish long scale)
Spelling & accents
Orthography rule of thumb: 16–19, 21–29, and all hundreds are commonly written as one word (dieciséis, veintidós, doscientos). Forms like "veinte y uno" are considered outdated.
Accents that matter a lot: dieciséis, veintidós, veintitrés, veintiséis.
Common mistakes
- cien vs. ciento: 100 = cien, but 101 = ciento uno.
- 21,000: not "veintiuno mil" → veintiún mil.
- 1,000,000: not "uno millón" → un millón.
- Missing accents: especially 16/22/23/26.
- Irregular hundreds: quinientos / setecientos / novecientos.