Writing in Spanish

The 8 Best Spelling Rules for Numbers in Spanish

The spelling rules for numbers differ from one language to another. When you speak several languages, it is common to mix up the rules and confuse the spelling of numbers.

Today we’ll show you some tips for spelling ordinal numbers in Spanish and spelling cardinal numbers in Spanish.

Ordinal numbers are numbers that indicate order or position in a sequence, for example, primero (first) or vigésimo (twentieth). Cardinal numbers express quantity in relation to the series of natural numbers, for example, uno (one) or veinte (twenty).

1. Separation With More Than Three Digits

When a number has four digits, the RAE recommends writing them together, but if there are more than four digits, leave a space between each group of three, never use a full stop or a comma for this purpose:




3 400





456 000

100 500 600

2. Concordance

Figures can be followed by nouns but remember that the word thousand is an adjective, so you will have to make the concordance as such:


Cuarenta miles de puestos de trabajo

(Forty thousand Jobs)


Cuarenta mil puestos de trabajo

3. Figures or Letters?

Don’t mix numbers and letters when using numerical adjectives:


40 mil kilogramos

Cuarenta 1000 kilogramos

(Forty thousand kilograms)


40 000 kilogramos

Cuarenta mil kilogramos

4. Symbols

When a number goes with a symbol, always leave a blank between the number and the symbol:





5 kg

100 %

5. Alternation

To express alternation between numbers to separate quantities, we will use the conjunctions o and u (or) when needed and never a slash:


Había 10/12 personas

Peso 80/81 kg

(There were 10 or 12 people

Weight 80 or 81 kg)


Había 10 o 12 personas

Peso 80 u 81 kg

6. Decimals

A comma is recommended to separate decimals, although the use of a full stop would be permitted.


67 982,89

7. Write With Numbers

Page numbers, years and street numbers. After all, in some contexts, the aim is to facilitate the work of others. For example, it is much easier for a postman to read C/ Conde Mariscal, 67.


Página ochenta de cuatrocientas

Calle Recoletos, veintitrés

(Page eighty of four hundred

Calle Recoletos, twenty-three)


Página 80 de 400

Calle Recoletos, 23

8. Write With Letters

Expressions are always written in letters, as are numbers in legal documents, to avoid confusion.


Cada 2 por 3


Cada dos por tres

(Every now and then)

From Numbers to Letters

Sometimes you may wonder how to write out numbers to letters in Spanish. Well, you can use iScribo’s spelling and grammar checker to make sure you write them properly. We advise you to learn the RAE rules before practising. Are you confident to write some numbers with letters in the comments?

Want more Spanish tips?

Get them direct to your inbox

Sign up for tips and tricks to perfect your Spanish writing skills. You’ll be writing like a native in no time.

Free Trial until 30 September 2021: Our subscription programme does not start until 1 October 2021. So, as long as you provide us with a feedback you can use our site for free until noon 30 September 2021 (GMT)