When to Spell Out Numbers in Writing: Important Rules and Examples

Last Updated on January 18, 2021

When to spell out numbers? Some authors prefer to write numbers as numerals instead of spelling them out since the former helps achieve a more concise text. Deciding whether or not to spell out a number is quite confusing. Generally, the number one rule is for the writer to express numbers consistently throughout the entire write-up. But for formality and appropriateness, check out the guidelines below to know when to spell out numbers in writing.

When to Spell Out Numbers

Rules and examples on when to spell out numbers

Spell Out the Number If

1. The number ranges from one to ten.

This is the prevailing rule when it comes to scientific and technical writing. However, for non-technical write-ups, numbers are usually spelled out if they are less than 101.


  • Kierra is the mother of those three beautiful ladies.
  • There’s only one way to find out.
  • The postman delivered eight mails for today.

2. The number is conveniently round.

Conveniently round, in this context, refers to the numbers that end in multiple zeros. Examples are the amounts in hundreds, thousands, millions, and so on. Instead of putting all the zeros, you can write the number as fully-spelled words. Whole millions or billions can be expressed as numerals with the words “million” or “billion” after it. The whole numbers may also be spelled out if it ranges from one to ten.


  • The manufacturing company produces one million plastic bottles every year.
  • According to statistics, the number of texts sent worldwide is 560 billion every month.
  • The concert hall can accommodate around ten thousand people.

3. The number is found at the beginning of the sentence.

Numbers that begin a sentence should be written in fully-spelled words. This is one fundamental rule that has to be followed all the time, no matter how small or large your number is. If you think the spelled-out number takes too much space for you, you would have to reconstruct your sentence so that the number would no longer be at the beginning.


  • Five little monkeys were jumping on the bed.
  • Nineteen forty-six was the year when the Philippines got its independence.
  • Twenty days is enough time for me to complete the project.

DO NOT Spell Out the Number If

1. You are referring to a year.

If the year is not found at the beginning of the sentence, you don’t have to spell it out. Write it in numerical form to express direct and concise information.


  • In 1946, the Philippines gained its independence.
  • The Cold War lasted from 1947 to 1991.
  • The couple promised to marry each other by the end of 2018.

2. The number has three or more digits.

This rule is specifically referring to numbers that occupy a considerable amount of space when written in words. Apart from taking more space, lengthy texts can either distract the reader or make the information less recognizable. Conveniently round numbers, as mentioned earlier, are exempted from this rule.


  • A total of 12,345 fans have attended the concert.
  • There are 8760 hours in a year.
  • According to the entrance exam results, 1,280 students have passed and entered the prestigious academy out of the 3,455 who tried taking the examination.

3. The number contains decimals.

For a more accurate and uncomplicated way of relaying information, amounts with decimals should be written as numerals.


  • The firm’s production increased by 3.5% because of the newly added machinery.
  • One meter is equal to 3.28 feet.
  • The guy drives his car at 40.5 miles per hour.

Other Rules

1. For values of measurement:

Values of measurement should be written in words if it is accompanied by its fully-spelled unit of measurement. If the abbreviation of the unit is used, you have to write the amount numerically.


  • She gained three kilograms after the summer vacation.
  • The third weightlifting contestant can lift 150 kg.
  • Mandy sells her pre-loved dresses for ten dollars.
  • The actual cost of one of Mandy’s dresses is $35.

2. For two numbers in a row:

When two numbers happen to be side by side with each other, you have to spell out one of the numbers. The selection as to which number should be spelled out depends on your choice. The primary purpose of this is to keep the reader from interchanging the two amounts.


  • There are 15 five-year-old children present in the kindergarten center today.
  • There are fifteen 5-year-old children present in the kindergarten center today.

When to Spell Out Numbers | Infographic

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