Large Text 18pt/24px Threshold Classifier

WCAG2 xlarge-text size category 18 pt=24 CSS pxor 14 ptbold=56/3 px; independent bold applicability, no physical PPI conversion or complete WCAG conformance. Explicit caller font/layout/reference context; not a shaping engine, actual page layout or accessibility certification.

Description

WCAG large-text size categories use CSS-equivalent point thresholds and distinguish bold from regular text.

WCAG large-text size categories use CSS-equivalent point thresholds and distinguish bold from regular text.^{[1, 2]}

This screen evaluates only that size category, which is one input to a contrast review.

When to use Large Text 18pt/24px Threshold Classifier

Use this tool when you need to reproduce the stated calculation from measured records or independently selected model inputs. Establish the font version, feature, layout, physical or CSS units, and matched reference basis needed for this calculation.

How to use Large Text 18pt/24px Threshold Classifier and understand its results

Establish the font version, feature, layout, physical or CSS units, and matched reference basis needed for this calculation.
Enter observedCssFontPx, independentlyBoldForWcag, following the field table and rules below, then run the tool.
Read wcagLargeTextSizeScreen, requiredCssPxForDeclaredWeight. Use the output meanings below to interpret units, signs, flags, and any nested result fields.
Correct reported input issues and run again. For a successful result, check the stated evidence coverage and assumptions before using it in your review.

Input field	Meaning	Value type	Requirement
observedCssFontPx	Observed CSS font px	number	Required
independentlyBoldForWcag	Independently bold for wcag	boolean	Required

Enter a nonnegative CSS font size in pixels and the independently established bold status. Use a threshold of 24 CSS pixels for regular text or 56/3 pixels for bold text; equality qualifies. The screen does not measure contrast or physical panel density.

threshold=bold?56/3:24; largeText=(cssPx≥threshold)

Symbols follow the input and output meanings and the calculation rules above.

Output field	Meaning	Value type
wcagLargeTextSizeScreen	Wcag large text size screen	boolean
requiredCssPxForDeclaredWeight	Required CSS px for declared weight	number

json

{
  "input": {
    "observedCssFontPx": 24,
    "independentlyBoldForWcag": false
  },
  "output": {
    "wcagLargeTextSizeScreen": true,
    "requiredCssPxForDeclaredWeight": 24
  }
}

Limitations and assumptions

The calculation uses declared units and font or layout assumptions. It does not shape glyphs, lay out actual pages, or certify accessibility or print quality.

Missing required fields, unknown fields, wrong types, and violated calculation rules are input issues. Numeric values must be finite; nonfinite results are rejected.

Alternative or Complementary methods

For a related review, use Minimum Body Size Accessibility pt Rule: Body-text size is one part of an accessibility or publishing review. This tool compares measured point sizes with your matched lower and upper bands; it does not prescribe a universal minimum. For a complementary step, use Device Pixel Ratio CSS px Lookup: Device pixel ratio compares matched device-pixel and CSS-pixel extents. It describes that observation rather than a physical pixels-per-inch measurement or a fixed value for a device name.

References

Large Text 18pt/24px Threshold Classifier — tool.io
Understanding WCAG 2.2 Contrast (Minimum) — W3C

Similar or alternative tools

Minimum Body Size Accessibility pt Rule
Body-text size is one part of an accessibility or publishing review. This tool compares measured point sizes with your matched lower and upper bands; it does not prescribe a universal minimum.
Device Pixel Ratio CSS px Lookup
Device pixel ratio compares matched device-pixel and CSS-pixel extents. It describes that observation rather than a physical pixels-per-inch measurement or a fixed value for a device name.