When do you use a slash mark?

This page reflects guidance from the sixth edition of the Publication Manual.

For the most current guidelines, see the Publication Manual of the American Psychological Association (7th ed.) and our Style and Grammar Guidelines page for the seventh edition.

Use a slash

to clarify a relationship in which a hyphenated compound is used.

  • the classification/similarity-judgment condition

to separate numerator from denominator

  • X/Y

to indicate per to separate units of measurement accompanied by a numerical value

  • 0.5 deg/s

to set off English phonemes.

  • /o/

to cite an unpublished work.

  • Freud (1923/1961)


Do not use a slash

when a phrase would be clearer

  • Each child handed the ball to her mother or guardian.
    Each child handed the ball to her mother/guardian.

for simple comparisons. Use a hyphen or short dash (en dash) instead.

  • test–retest reliability
    test/retest reliability

more than once to express compound units. Use centered dots and parentheses as needed to prevent ambiguity.

  • nmol • hr-1 • mg -1


(adapted from the sixth edition of the APA Publication Manual, © 2010)