Should Numbers Be Spelled Out?
Here are the general rules on whether to write a number in words or numerals (figures) in formal writing:
1. Spell out single-digit numbers (zero to nine). Write all other numbers as numerals.
- Only eight students opted to study philosophy this year.
- The two sides scored three goals each.
- We have received 314 applications so far.
- The first batter made 42 runs, and the second one made 11.
2. Spell out a number at the start of a sentence.
- Forty-two people have applied so far for this position.
- One hundred thirteen people have signed the petition.
- Sixty-seven thousand four hundred thirteen citizens voted today.
If this feels clunky, reword.
- In all, 67,413 citizens voted today.
3. To aid with readability, hyphenate two-digit numbers when spelling them out, even when part of a larger number.
- Seventy-seven people voted for the new candidate.
- Three thousand twenty-two people turned up at the party.
- Forty-nine million is the magic number.
4. Follow the rules listed above for whole numbers used with million, billion, trillion, and so on.
- This planet is home to nine billion human beings.
- We have received 10 million applications so far.
- More than 345 million residents took the survey.
5. To improve clarity, skip the and in numbers such as 7,543 when spelling them out.
- Seven thousand five hundred
andforty-three users liked her post. - Four hundred
andfourteen people have applied.
6. Maintain consistency in using numerals or words within a sentence. If any of the numbers within one category is greater than nine, use numerals for all numbers within that category.
- The first batter made 42 runs, and the second one made only 4.
- For breakfast today, I ate 14 apples and 3 oranges.
But if the only reason you spell a number out is because it is at the start of a sentence, you can use numerals for the following numbers even if they are of the same category.
- Four hundred three of 500 students graduated, 91 failed, and 6 dropped out.
Don’t be afraid to reword to improve readability.
- Of 500 students, 403 graduated, 91 failed, and 9 dropped out.
Exceptions exist. The different style manuals also have their own specific rules about how to show numbers in writing. In this article, we use examples to discuss these and additional guidelines, such as how to handle fractions, decimals, percentages, number series, dates, time, money, and other measured quantities.
Exceptions in Chicago style
The Chicago Manual of Style (followed in academic and book editing) specifies some exceptions to the general rules above.
1. Spell out whole numbers from zero to one hundred (instead of only those from zero to nine).
- The first batter made forty-two runs, and the second one made eleven.
- For breakfast today, Rita ate fourteen caterpillars and three centipedes.
- We have received seven applications so far.
2. Also spell out whole numbers followed by hundred, thousand, or hundred thousand.
- Lulu hadn’t expected seven hundred people to turn up at the party.
- About sixty-seven thousand citizens voted today.
- Did you know this stadium could hold two hundred thousand people?
Use numerals as usual for other numbers greater than one hundred.
- Lulu hadn’t expected 710 people to turn up at the party.
- A total of 67,413 citizens voted today.
- Did you know that 210,619 people watched the game today?
Exceptions in AP style
The AP Stylebook (followed in U.S. journalism and corporate communication) suggests using numerals with million, billion, etc., except at the start of a sentence.
- More than 3 billion people have watched this video.
- We have 17 million subscribers.
- Tumkin earned 173 million dollars last year.
Ordinal numbers
Add st, nd, rd, and th as appropriate to create ordinal numbers (which indicate the position of something in a sequence). The general rules about using words or numerals apply to ordinal numbers as well.
- Poco is fifth in line to the throne.
Spell out numbers from zero to nine.
- The 45th house on this street is listed for rent.
Use numerals for numbers greater than nine.
- The 500th customer wins a surprise gift.
- The 14,423rd ticket won the lottery.
- Thirteenth place isn’t so bad!
Spell out numbers at the start of a sentence.
Most style manuals recommend displaying the letters in ordinal numbers as regular text rather than superscripts (to ensure uniform presentation across fonts.)
- Greece is the
33rd/33rd country on the list.
Measurement
With units of measurement (including SI units), use numerals, especially when writing in a technical context. In particular, always use numerals with abbreviated units.
- This mushroom weighs 7 kg.
- The nearest airport is 8 km away.
- The creature’s wings measure 5 cm exactly.
- Rita’s lap time: 343 s
In nontechnical writing, treat quantities such as distances, time periods, and lengths based on the general rules.
- In eight minutes, the bell will ring.
Spell out numbers up to nine.
- I live 15 miles away from here.
Use figures for numbers 10 and greater (except in Chicago style).
- Unfortunately, I am only four feet ten.
More informal: four foot ten or four ten
- I need 10 cardboard boxes, each at least two feet wide.
Dates
In dates, spell out the month but write the day and year in numerals.
- She was born in Port Louis on May 5, 1985.
- Maya’s book will become available in bookstores across the country on January 15.
Avoid using ordinal numbers in dates in formal texts (May 5 instead of May 5th or May 5th).
- The cure was found on July 7
th, 2020.
British style is day-month-year. The same rules apply: write the day and year in numerals; spell out the month. Don’t use ordinal numbers for dates in formal writing.
- Farley was abducted by aliens on 31 October 2024.
When writing as it would be read aloud (for example, in creative writing), follow the general rules.
- Farley was born on the fifth of May in 1985.
Use words instead of numerals for single-digit numbers.
- The mill burned down on the 15th of January 1973.
orThe mill burned down on the fifteenth of January 1973.Use numerals for numbers from 10 onwards, except in Chicago style.
Years
Use numerals for years, except at the start of a sentence.
- The Space Age began in 1957.
- When I look back, I realize that 2024 was the year I grew up.
- Nineteen fifty-seven marked the start of the Space Age.
- Twenty twenty-four was the year I grew up.
Decades
Decades can be written in words or numerals.
- fashions of the 1970s
- the roaring ’20s
- the music of the sixties
In names of decades and centuries, an apostrophe may or may not be placed before the s.
- the 1600s or the 1600’s
In most formal styles (including Chicago, APA, and AP), the apostrophe is omitted.
Centuries
Names of centuries can either be spelled out or referred to using numerals. Do not capitalize.
- We are people of the twenty-first century.
Note the hyphen and lack of capitalization.
- I have signed up for a course on seventeenth-century philosophy.
- She lived and died in the 20th century.
Rules for how to write centuries vary across style manuals. The Chicago Manual of Style and the MLA Handbook recommend spelling out the names of centuries.
- The fifth century was a time of political instability in Eurasia.
- The period from the twentieth to the twenty-seventh century is called the Space Age.
The AP Stylebook follows the general rule: spell out single-digit century names and use numerals for double digits. Stay consistent in usage within a text.
- People in the ninth century must have thought they lived in modern times.
- The 18th century was a time of conquest and revolution.
Time
Use numerals to emphasize exact times on the clock face.
- It was 2 p.m. when I got home.
- The train leaves at 10:13 a.m.
With o’clock, you may use either words or numerals.
- It was two o’clock in the afternoon when I got home.
Chicago recommends using words instead of numerals with o’clock.
- Farley’s alarm rang at 5 o’clock.
In AP style, use numerals.
You can also spell out quarter and half hours in text and use words for the numbers.
- The space train leaves at half past four.
orThe space train leaves at four thirty.
- Last orders are at a quarter to eleven.
The article a here is optional.orLast orders are at ten forty-five.
- She left work at a quarter past six today.
orShe left work at six fifteen.
Noon and midnight are usually referred to as such instead of as 12 noon and 12 midnight.
- Will you be here by noon?
- It was already midnight, but the party had barely started.
Stay consistent in referring to hours and minutes within a category.
- Poor: The hoverbus leaves at a quarter to one, 2:30, and 4 o’clock every day.
- Better: The hoverbus leaves at a quarter to one, half past two, and four o’clock every day.
- Best: The hoverbus leaves at 1:45, 2:30, and 4:00 p.m. every day.
Use numerals when exact times are important.
When speaking of time using the 24-hour system, use numerals. A colon appears between the hours and minutes only if the word “hours” is not used.
- The train leaves at 1800 hours.
“Eighteen hundred hours” in speech.
- The train leaves at 18:00.
Read aloud as “eighteen hundred.”
- The Durandians landed at 1635 hours on July 11, 2073.
- The Durandians landed at 16:35 on July 11, 2073.
Read simply as “sixteen thirty-five.”
Decimals
Express decimal fractions in numerals.
- In 2015, the country saw 1.15 boys born per girl.
Read aloud as “one point one five.”
- The mean of this sample is 2.83.
When the fraction is less than one, a zero is normally inserted before the decimal point.
- In 2015, the country saw 0.97 girls born per boy.
All quantities other than 1 are considered plural, even those less than 1.
- On average, each class loses 0.6 students per semester.
- The can loses 3.6 units of air per year.
Fractions
Spell out and hyphenate simple fractions to improve readability.
- I have graded three-fifths of the papers.
Note the s for the plural: three fifths.
- In response to the pay cut, one-third of the workers have gone on strike.
We are referring to a third of the total, so third is singular.
- For this bill to pass, we require a two-thirds majority.
- She spent half her morning on the phone.
For mixed or improper fractions, use numerals.
- We need an envelope at least 4¼ inches long.
- Maya grew up to be only 4 feet 9½ inches tall, which meant she couldn’t be an astronaut.
- I am told that 22/7 is merely an approximation of pi.
Percentages
To express a percentage, use numerals, except at the start of a sentence.
- Overall attendance was 81 percent this semester.
- Only 20% of the participants in this study were given a placebo.
- Twenty percent of votes remain uncounted.
Use words instead of numerals at the start of a sentence.
If the percentage contains digits after the decimal point, avoid using it at the start of a sentence.
- Poor: 20.5 percent of the total votes remain uncounted.
- Better: Of the total votes, 20.5 percent remain uncounted.
No space is left between the numeral and the symbol %, except in scientific and technical publications that follow SI style.
Money
Spell out amounts of money of less than 10, and use numerals for the rest. Also remember to use words instead of numerals if the amount appears at the start of a sentence.
- Anita lent me five dollars for cab fare.
- Would you believe this cost only 42 euros?
- I would never pay 10 million for a condo.
- Is two million too much to spend on a wedding?
Chicago’s exceptions apply here as well.
The AP Stylebook suggests always using numerals with million, billion, etc., and with units of money.
- At 3 million, it is not a large population.
- This skirt costs just 6 dollars.
Series
Numbers that follow nouns to refer to things in a series are always written as numerals.
- Chapter 2
the second chapter of a series of chapters
- Episode 23
- Experiment 3
- Page 4
- Table 1