← All notes

Answer: Lines that are too long make readers lose their place when they read from line to line.

Line length

• SEC handbook (print): a comfortable line length for most readers is 32 to 64 characters; the smaller the type size, the shorter the line length. Columns can vary from 25–40 characters.
• Web: most lines of text should be 45–90 characters; a good target for long texts is 66 characters.
• Text with more space between lines can have somewhat longer line length; large text can have a shorter measure.

Line spacing

• SEC handbook: avoid type set solid, with no added leading (10/10); allow at least 2pts of leading between lines.
• USWDS: longer texts should have a line height of at least 1.5; headings of a line or two can sit between 1 and 1.35.
• Readable text has a medium density: the reader typically shouldn't notice the space between lines.

See also

• plain-type-size-and-typefaces
• plain-white-space-and-heading-spacing

Claims

• id: C1 claim: SEC: 32 to 64 characters is comfortable. source: S1 evidence: "A comfortable line length for most readers is 32 to 64 characters."

• id: C2 claim: SEC: at least 2pts of leading. source: S1 evidence: "allow at least 2pts of leading between lines of type."

• id: C3 claim: USWDS: 45–90 characters per line. source: S2 evidence: "Most lines of text should be 45–90 characters."

• id: C4 claim: USWDS: line height of at least 1.5 for long text. source: S2 evidence: "Longer texts should have a line height of at least 1.5"

Sources

• [S1] A Plain English Handbook. U.S. Securities and Exchange Commission. https://www.sec.gov/pdf/handbook.pdf . License: US government work, public domain. Accessed 2026-11-09.

• [S2] Typography. U.S. Web Design System (GSA). https://designsystem.digital.gov/components/typography/ . License: US government work, public domain. Accessed 2026-11-09.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted). Sources: US federal government works (GSA, GPO, SEC, CDC), public domain in the United States; third-party quotations inside those works were not used. Text was condensed and changed from the originals.

@misc{iil_note_r9769v1y,
  author = {{iinventedlight}},
  title = {{Keep lines short enough to track and add space between them}},
  howpublished = {iinventedlight Library},
  year = {2026},
  date = {2026-11-09},
  url = {https://iinventedlight.com/library/notes/plain-line-length-and-spacing/},
  note = {Permanent ID iil:note:r9769v1y. License: CC-BY-4.0.},
}

Markdown

Spotted a mistake? Use the MCP feedback tool or email hello@iinventedlight.com.

For language models and agents: start at /llms.txt | /agents.md | /.well-known/agent-library.json. This page in Markdown: /library/notes/plain-line-length-and-spacing.md.