How Many Spaces After a Period? One vs. Two Spaces

The overwhelming majority of contemporary style guides and word processors advise using a single space between typed sentences. When in doubt, use single spacing in research papers, essays, and your creative writing. This is true regardless of whether your sentence ends in a period, a question mark, or some other form of punctuation. Single spaces should also follow commas, as well as periods after abbreviations.

For much of the twentieth century, typographers used double spacing after each sentence, but single-space formatting has become the standard in twenty-first-century word processing. The debate over the number of spaces has waned over the years, but some adherents to the two-space convention (known as “two spacers”) argue the extra space signals the end of a complete thought more effectively.

The origin of the two-space rule coincides with the evolution of the printing press. The eleventh-century Chinese invention of movable typesetting revolutionized printing. By the nineteenth century, style guides sprouted up to set standards for typography, and these guides dictated rules for sentence spacing. Several—including the British English style guides by Jacobi and the American English style guides by MacKellar, Harpel, and De Vinne—stipulated that sentences be separated by white space the size of an em dash. Typesetters called this an “em space.” At the same time, a number of French publishing houses used single spacing, which prompted the term "French spacing."

With the advent of the personal typewriter, the em space became impractical. Early typewriters used monospaced fonts, which did not provide the amount of space needed for traditional sentence spacing. Typists solved this conundrum by typing two spaces at the end of a sentence. The two-space rule took hold in the early twentieth century and became the norm in many high school typing classes. Eventually, sophisticated typewriters and word processing software like Microsoft Word introduced proportional fonts, which made it easier to distinguish the period at end of a sentence as a full stop. Out of habit, many typists and stylebooks stuck with the extra space for perceived readability.

Contemporary style guides overwhelmingly recommend single spaces, rather than double spaces, between sentences. This includes:

1. 1. Associated Press Stylebook (also known as the AP Stylebook) by the Associated Press
2. 2. MLA Handbook by the Modern Language Association
3. 3. The Chicago Manual of Style by the University of Chicago
4. 4. APA Style by the American Psychological Association
5. 5. The Microsoft Manual of Style for Technical Publications by Microsoft
6. 6. The Gregg Reference Manual by William A. Sabin

Word processing software also steers users toward single spacing. Microsoft Word flags a double space as an error. Apple computers feature a shortcut where you can double-tap the spacebar to produce a period followed by a single space. This even applies to monospace typefaces like Courier New.

Become a better writer with the MasterClass Annual Membership. Gain access to exclusive video lessons taught by the world’s best, including Salman Rushdie, Neil Gaiman, Walter Mosley, Margaret Atwood, Joyce Carol Oates, Dan Brown, and more.