Lines of type that are too long or too short slow down reading and comprehension. Type size, margins, gutters, and number of columns help determine the line length of a publication. Increase readability by following a few guidelines and trying out some formulas for determining the ideal line length for your text.
Time Required: As long as it takes to try out different font sizes and column widths to find ideal line length
- Apply the alphabet-and-a-half line length rule.
The alphabet-and-a-half rules places the ideal line length at 39 characters regardless of type size. Measure the line length in inches or picas for your chosen body copy font using the alphabet-and-a-half rule. This is one of the measurements you'll use in finding the ideal line length/column width for your publication.
- Apply the points-times-two line length rule.
Take the type size of your body text and multiply it by two. The result is your ideal line length in picas. That is, 12 point type would have an ideal line length of 12x2 or 24 picas (approx. 4 inches).
- Compare the line length measurements for method 1 and 2.
Set a column width in your publication that falls within the range established by each formula. Keeping column widths and line lengths within this range will help insure the most readable text.
- Adjust font size and column widths to accommodate best line length.
If your chosen body copy font and desired layout fall too far outside the ideal line length as determined by applying methods 1 and 2, consider adjusting your font size or changing your layout to find a line length that is closer to the ideal.
- See how these line length formulas work.
View the supporting illustration to see these line length formulas in action.
- These are guidelines not hard-and-fast line length rules.
A longer or shorter line length may be justified in some designs; however, using these formulas will give you an idea of what line length range is most reader-friendly for your chosen font.
- Line length is not the only consideration.
The shape of the font, letter spacing, and word spacing also affect readability and help in determining the best line length.