What is the minimum contrast ratio for large text?

What is the minimum contrast ratio for large text?

• A. 2:1
• B. 3:1
• C. 4.5:1
• D. 7:1

Answer: (B)

The key idea is readability for users with low vision: contrast ratio measures how well text stands out from its background. For large text, the standard allows a lower threshold, specifically a minimum contrast ratio of 3:1. Large text is typically defined as 18-point text or 14-point bold (roughly 24 pixels). So any color pairing that meets at least 3:1 will be considered accessible for large text. Normal text, by contrast, requires a higher ratio of 4.5:1. Looking at the options, 2:1 falls short, while 4.5:1 and 7:1 exceed what's required for large text (though they would still satisfy the rule). Therefore, 3:1 is the minimum contrast ratio needed for large text.

The key idea is readability for users with low vision: contrast ratio measures how well text stands out from its background. For large text, the standard allows a lower threshold, specifically a minimum contrast ratio of 3:1. Large text is typically defined as 18-point text or 14-point bold (roughly 24 pixels). So any color pairing that meets at least 3:1 will be considered accessible for large text. Normal text, by contrast, requires a higher ratio of 4.5:1. Looking at the options, 2:1 falls short, while 4.5:1 and 7:1 exceed what's required for large text (though they would still satisfy the rule). Therefore, 3:1 is the minimum contrast ratio needed for large text.