How Many Spaces Should Be After a Period?
Here is a client question received today, which I often hear in business writing courses:
Years back, I was taught that two spaces should follow a period in a paragraph. I was working on a document and noticed the author used both one space and two spaces between sentences. I changed all of the occurrences to two spaces, but in discussions with others, I was told a single space is now the new norm.
Which one is correct? One or two spaces in business writing?
I have a clear and easy answer for this question: One space is correct.
UPDATE: As of April 24, 2020, Microsoft has settled the great space debate, and sided with everyone who believes one space after a period is correct, not two. The software giant has started to update Microsoft Word to highlight two spaces after a period as an error, and to offer a correction to one space. Microsoft recently started testing this change with the desktop version of Word, offering suggestions through the Editor capabilities of the app.
Additionally, the American Psychological Association’s Publication Manual, after decades of recommending two spaces changed their recommendation to one space in its most recent update in October, 2019.
How Two Spaces Evolved
If you learned to type on a typewriter before word processors became the norm, two spaces after a period were required and taught as correct. The extra space was needed to delineate the beginning of a new sentence because the spacing between words was uneven on a typewriter.
If you didn’t learn to type on a typewriter, you’re likely using two spaces after the period because you’re modeling the writing of someone who did learn to write on a typewriter.
Typewriters gave every character the same space on the screen. This is called monospaced typesetting.
In contrast, word processing software uses proportionally spaced fonts, which automatically adjust the spacing between characters to accommodate the varying width of letters. This is called proportional typesetting.
Here is an example of monospaced typesetting from a typewriter:
Now here is the same sentence using a proportional font from word processing software:
As a rule, a monospace font always takes more space on the screen:
Because there is so much extra spacing in the typewritten monospace font, writers using typewriters needed the extra space after punctuation to indicate a full stop, such as a period, question mark, or exclamation point.
If you’re using any word processing software on a computer, such as Microsoft Word, Apple Pages, or Google Docs, there is no need for more than one space after the period. All of these tools will space letters and sentences appropriately for you if you use one space after the sentence.
Using two spaces will actually distort your typeset.
We took a poll. Here are the results.
Why Using Two Spaces Hurts Your Writing
1. It makes your writing look dated.
Word processing has been around for a long time and we should update our writing to reflect current tools.
The wonderful blog The Cult of Pedagogy explains this well in an article entitled, Nothing Says Over 40 Than Two Spaces after a Period! (Side note: A fair question is “What’s wrong with being over 40?” The author addressed this implicit denigration of older people and the snarky tone in a follow-up article.)
The lesson to business writers is that two spaces date-stamps our writing.
An extra space between sentences creates a river of white in marketing documents, diminishing the impact.
Dianna Huff, a respected and experienced manufacturing marketing writer recently affirmed this on Twitter:
2. Nearly all style guides agree that one space is correct.
Microsoft Manual of Style for Technical Publications
The Chicago Manual of Style
The Associated Press Stylebook, which is the most accepted style guide for business writing
The Gregg Reference Manual
The Publication Manual of the American Psychological Association (APA) was the only style guide that overtly recommended two spaces after a period, and even that long-time holdout for two spaces changed its guideline to one space in its 2019 update. The MLA Handbook for Writers of Research Papers (MLA) waffles. Interestingly, all examples MLA presents in their guide use just one space and it states that most publishers’ guides recommend one space. It adds the contradictory disclaimer that "there is nothing wrong with using two spaces after concluding punctuation marks unless an instructor asks you to do otherwise."
NOTE: both APA and MLA are primarily academic writing guides, not business writing guides. Academic writing also uses different text justifications and indented paragraphs, requiring more white space between sentences to differentiate.
For business writing, follow the lead of logic and major style guides. Use one space after closing punctuation.
How to Replace Two Spaces with One Space
Old habits can be difficult to break, of course, but with focus one space will become your natural impulse. What if you find it hard to use one space after many years of adding two spaces after a full stop or colon?
Use the "Find and Replace" option in your word processor (Control + F on most systems) to remove the extra space. In more recent versions of Word, look for the Replace in the Home ribbon at the top of the screen.
In the “Find what” tab, type period (.) followed by two empty spaces (Spacebar). In the “Replace with” tab type period (.) followed by one empty space.
If you have used double space with other punctuation marks (!?:) make sure to replace them as well.
Or, use a good grammar and spell check tool such as Grammarly, which will flag the incorrect two spaces for you.
About the author
Mary founded Instructional Solutions in 1998, and is an internationally recognized business writing trainer and executive writing coach with two decades of experience helping thousands of individuals and businesses master the strategic skill of business writing. She excels at designing customized business writing training programs to maximize productivity, advance business objectives, and convey complex information. She holds a B.A. in English from the University of Rhode Island, an M.A. in English Literature from Boston College, and a C.A.G.S. in Composition and Rhetoric from the University of New Hampshire.