Numbers in Italian

Italian numbers are pretty easy to remember, except for a few irregularities.

The base numbers are:

0 zero
1 uno
2 due
3 tre
4 quattro
5 cinque
6 sei
7 sette
8 otto
9 nove
10 dieci

The numbers 11-19 have an irregular form:

11 undici
12 dodici
13 tredici
14 quattordici
15 quindici
16 sedici
17 diciassette
18 diciotto
19 diciannove

The two digit numbers with the 0 (zero) ending are irregular too:

20 venti
30 trenta
40 quaranta
50 cinquanta
60 sessanta
70 settanta
80 ottanta
90 novanta

To create two digit numbers you just have to do an addition:

36 trenta+sei → trentasei
42 quaranta+due → quarantadue
75 settanta+cinque → settantacinque

Exceptions are the two digit numbers where the second number is 1 (uno) or 8 (otto). In these cases the last vowel of 20 (venti), 30 (trenta), 40 (quaranta), and so on is always dropped.

21 venti+uno → ventuno
88 ottanta+otto → ottantotto
51 cinquanta+uno → cinquantuno
68 sessanta+otto → sessantotto

Another graphic exception is the acute accent put on the numbers ending with 3 (tre):

93 novanta+tre → novantatré
53 cinquanta+tre → cinquantatré

The three digit numbers are easily created, adding the word cento to the first number except for 100:

100 cento
200 due+cento → duecento
300 tre+cento → trecento
400 quattro+cento → quattrocento
500 cinque+cento → cinquecento
600 sei+cento → seicento
700 sette+cento → settecento
800 otto+cento → ottocento
900 nove+cento → novecento

To create other three digit numbers you just have to do an addition:

111 cento+undici → centoundici
317 tre+cento+diciassette → trecentodiciassette
521 cinque+cento+venti+uno → cinquecentoventuno
784 sette+cento+ottanta+quattro → settecentoottantaquattro

The numbers in thousands are easily created, adding the word mila to the first number except for 1,000:

1000 mille
2000 due+mila → duemila
3000 tre+mila → tremila
4000 quattro+mila → quattromila
5000 cinque+mila → cinquemila
6000 sei+mila → seimila
7000 sette+mila → settemila
8000 otto+mila → ottomila
9000 nove+mila → novemila
10.000 dieci+mila → diecimila
21.000 venti+uno+mila → ventunomila
200.000 due+cento+mila → duecentomila

To create other numbers you just have to do a simple addition:

1998 mille+nove+cento+novanta+otto → millenovecentonovantotto
2020 due+mila+venti → duemilaventi
7856 sette+mila+otto+cento+cinquanta+sei → settemilaottocentocinquantasei
327.463 tre+cento+venti+sette+mila+quattro+cento+sessanta+tre → trecentoventisettemilaquattrocentesessantatré

Milione (million) and miliardo (billion) are created with two words, first the root number and then the milione/miliardo word, which can become milioni/miliardi if the root number is bigger than 1:

Un milione (one million)
Un miliardo (one billion)
Tre milioni (three millions)
Cinque miliardi (five billions)