Reference number
ISO 24509:2019
International Standard
ISO 24509:2019
Ergonomics — Accessible design — A method for estimating minimum legible font size for people at any age
Edition 1
2019-10
Read sample
ISO 24509:2019
69766
Published (Edition 1, 2019)
This publication was last reviewed and confirmed in 2025. Therefore this version remains current.

ISO 24509:2019

ISO 24509:2019
69766
Language
Format
CHF 181

Abstract

This document provides a method for estimating minimum legible font size for single characters, but not for words or sentences, in self-luminous or reflected mode, used in documents, products labels, signs, and displays for people at any age and in any viewing condition in which viewing distance, luminance and contrast are varied.

This document applies designing and evaluating legibility of single characters for people at any age who have no pathological disorders in their eyes, but not for people with visual impairments such as low vision. The application is specifically directed to, but not limited to, the cases of printed materials where fixed font size is used.

Applicability of the method to other languages is given in Annex F.

General information

  •  : Published
     : 2019-10
    : International Standard confirmed [90.93]
  •  : 1
     : 37
  • ISO/TC 159/SC 4
    13.180 
  • RSS updates

Got a question?

Check out our Help and Support