Accessible Font Size Calculator
Minimum readable body and large-text sizes across print, web and presentations — accessibility-grounded.
16px is the de-facto web body-text floor — browsers default to it for good reason, and shrinking below it for 'cleaner' design hurts readability and accessibility. WCAG's 'large text' threshold (24px/18.66px bold) matters because large text gets a relaxed 3:1 contrast requirement. Always size in relative units (rem/em) so users who set bigger system fonts aren't overridden.
Formula
For general information only — not medical advice, a diagnosis or a treatment plan. Consult a qualified healthcare professional before making health, diet, medication or exercise decisions.
Minimum readable body and large-text sizes across print, web and presentations — accessibility-grounded. The Accessible Font Size Calculator is a free, private accessible font size tool — every result computes instantly in your browser with no sign-up and no data upload.
About Accessible Font Size Calculator
16px is the de-facto web body-text floor — browsers default to it for good reason, and shrinking below it for 'cleaner' design hurts readability and accessibility. It applies web body ≥16px; WCAG large = 18.66px bold / 24px; print ≥10–12pt. Use the Accessible Font Size Calculator to get an instant, clearly-explained result with the working shown step by step — free, private and with the source method cited.
How to use Accessible Font Size Calculator
- 1Enter your details in the Accessible Font Size Calculator input fields above.
- 2The result updates instantly with the working and reference bands shown.
- 3Adjust any value to explore how it changes the outcome — it's free and unlimited.
Why use Accessible Font Size Calculator?
- ✓Instant accessible font size result that recomputes as you type — no waiting, no page reloads
- ✓100% client-side: your health data never leaves your browser
- ✓Shows the actual formula and your numbers substituted in, so you can see exactly how the result is reached
- ✓Based on published, citable sources (WCAG 2.1; web typography accessibility guidelines)
- ✓Free forever with no sign-up, account or app install
Frequently asked questions
How does the Accessible Font Size Calculator work?+
16px is the de-facto web body-text floor — browsers default to it for good reason, and shrinking below it for 'cleaner' design hurts readability and accessibility. The calculation uses the formula: web body ≥16px; WCAG large = 18.66px bold / 24px; print ≥10–12pt. Everything runs instantly in your browser as you type — your inputs are never uploaded.
Is the Accessible Font Size Calculator accurate, and what is it based on?+
The method is traceable to authoritative sources: WCAG 2.1; web typography accessibility guidelines. Results are estimates — individual variation always applies, so treat the output as a well-grounded starting point.
Is the Accessible Font Size Calculator free and private?+
Yes. It's completely free with no sign-up, and all computation happens locally in your browser, so none of your health data ever leaves your device.
Can I use this for medical decisions?+
This tool is for general information only and is not medical advice. Always consult a qualified healthcare professional before making health decisions.
What can I use the Accessible Font Size Calculator for?+
It's commonly used for accessible font size, minimum font size web, readable text size. Minimum readable body and large-text sizes across print, web and presentations — accessibility-grounded.
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