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Numbers in APA

Note: This page reflects the 6th edition of the APA manual, which is now out of date. It will remain online until 2021, but will not be updated. There is currently no equivalent 7th edition page, but we're working on one. Thank you for your patience. Here is a link to our APA 7 "General Format" page.

In general, APA style recommends using words to express numbers below 10, and using numerals when expressing numbers 10 and above. See below for a more extensive list.

Numbers expressed as numerals

In addition to expressing numbers 10 and above, the following are other instances when you would use numerals rather than words:

Numbers mentioned in the abstract, a table, or a figure in the paper (this allows for brevity) 

This study consisted of 8 tests.

Numbers that immediately precede a unit of measurement

2.54 cm, 1.5 gal

Numbers that represent statistical or mathematical functions, fractional or decimal quantities, percentages, ratios, percentiles, and quartiles

Divided by 10

0.5

50% of the participants

a ratio of 10:1

the 10th percentile

numbers that represent time, dates, ages, scores and point values on a scale, exact sums of money, and numerals

2 hr 30 min

10:00 am

50-year-olds

A 10-point scale

$100

Exception: Use words for approximations of numbers of days, weeks, months, or years

Roughly six months ago

Numbers that denote a specific place in a numbered series, parts of books and tables, and each number in a list of four or more numbers

Illustration 1

Numbers expressed as words

In addition to using words to express numbers below 10, use words to also express:

Numbers beginning a sentence, title, or text heading

Fifteen participants were in the control group.

Common fractions

Three fourths of the population

Common phrases or groups

Seven Wonders of the World

The Three Musketeers

Other Rules Concerning Numbers

Here are a few more rules concerning numbers to adhere to as you follow APA style:

If you are using two modifiers against a noun, use a combination of both numerals and words

Three 5-point scales

If you’re unsure which modifier to write and which to express numerically, try it both ways. Be sure the way you express the numbers is in the clearest way possible.

Place a zero before a decimal fraction less than 1 if the statistic can exceed 1.

0.54 in

If the statistic cannot exceed 1, you do not need a zero.

p = .85

For more specific guidelines, talk to your instructor or refer to the Style Manual.