# Numbers in Esperanto – number to words converter

Source: https://esperantopedia.org/tools/numbers/
Language: en
Updated: 2026-10-07

> Write any number in Esperanto words: 1887 = mil okcent okdek sep. Also ordinals (unua), fractions (duono) and multiples (duobla).

Esperanto numbers are fully regular: you need only **thirteen words** – *nul, unu, du, tri, kvar, kvin, ses, sep, ok, naŭ, dek, cent, mil* – to say any number below a million. Tens and hundreds are written as one word (*dudek* = 20, *tricent* = 300); everything else is written separately (*dudek tri* = 23).

## How Esperanto numbers are built

| Number | Esperanto | Rule |
|---|---|---|
| 1–9 | unu, du, tri, kvar, kvin, ses, sep, ok, naŭ | basic words |
| 10 | dek | basic word |
| 11 | dek unu | ten + one |
| 20 | dudek | two-ten, one word |
| 23 | dudek tri | twenty + three |
| 100 | cent | basic word |
| 300 | tricent | three-hundred, one word |
| 1000 | mil | basic word |
| 2000 | du mil | *mil* is written separately |
| 1 000 000 | unu miliono | *miliono* is a noun |
| 2 000 000 | du milionoj | plural *-j* |
| 3,5 | tri komo kvin | decimal comma *komo*, digits after it one by one |

The full guide, with ordinals, dates and telling the time, is on the [Esperanto numbers](https://esperantopedia.org/grammar/numbers/) page.

## Endings that turn numbers into other words

| Ending | Meaning | Example |
|---|---|---|
| -a | ordinal | *tria* – "third" |
| -e | adverb | *unue* – "firstly" |
| -obl- | multiple | *duobla* – "double" |
| -on- | fraction | *kvarono* – "a quarter" |
| -op- | group | *triope* – "in threes" |
| -o | noun | *dekduo* – "a dozen" |

## Common questions

### How do you say 2026 in Esperanto?
*Du mil dudek ses.* The year 1887, when Esperanto was published, is *mil okcent okdek sep*.

### How do you write ordinal numbers like "21st"?
Add *-a* to the number: *dudek-unua* (or *dudek unua*) means "twenty-first". In figures you can write *21-a*.

### What is a billion in Esperanto?
*Miliardo* is 1 000 000 000 (10⁹). *Biliono* means 10¹², following the long scale used in most of Europe, so *biliono* is not an English "billion".

## Sources

- [Plena Manlibro de Esperanta Gramatiko (PMEG): Nombroj](https://bertilow.com/pmeg/gramatiko/nombroj/index.html)
- [Fundamento de Esperanto – Gramatiko, rule 4](https://www.akademio-de-esperanto.org/fundamento/gramatiko_angla.html)