Minimum Body Size Accessibility pt Rule
Measured body type font size against independently verified caller accessibility/publishing band, no standard universal minimum font size in points. Missing evidence retained as explicit indices, not confirmed zero margin. Explicit caller font/layout/reference context; not a shaping engine, actual page layout or accessibility certification.
Description
Body-text size is one part of an accessibility or publishing review.
Body-text size is one part of an accessibility or publishing review.1
This tool compares measured point sizes with your matched lower and upper bands; it does not prescribe a universal minimum.
When to use Minimum Body Size Accessibility pt Rule
Use this tool when you need to identify observed values outside a supplied band and keep unknown evidence visible. Establish the font version, feature, layout, physical or CSS units, and matched reference basis needed for this calculation.
How to use Minimum Body Size Accessibility pt Rule and understand its results
- Establish the font version, feature, layout, physical or CSS units, and matched reference basis needed for this calculation.
- Enter observedMeasuredBodyPointSize, callerMeasuredBodyPointSizeLower, callerMeasuredBodyPointSizeUpper, knownMeasuredBodyPointSizeFlags, following the field table and rules below, then run the tool.
- Read signedKnownMargins, knownReviewIndices, unknownIndices. 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 |
|---|---|---|---|
| observedMeasuredBodyPointSize | Observed measured body point size | list of number | Required |
| callerMeasuredBodyPointSizeLower | Caller measured body point size lower | list of number | Required |
| callerMeasuredBodyPointSizeUpper | Caller measured body point size upper | list of number | Required |
| knownMeasuredBodyPointSizeFlags | Known measured body point size flags | list of number | Required |
Use aligned nonempty observation, lower-bound, upper-bound, and known-flag lists. Flags are binary zero or one and every lower bound must be at most its upper bound, including unknown entries. For known observations, return the smaller signed distance to the two bounds. A positive margin is inside the band, zero is on a boundary, and a negative margin is outside. Return zero-based review indices only for known values strictly outside the band. Unknown entries receive zero margin placeholders and separate unknown indices; these zeros do not confirm compliance.
margin_i=known_i?min(observed_i−lower_i,upper_i−observed_i):0 Symbols follow the input and output meanings and the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| signedKnownMargins | Signed known margins | list of number |
| knownReviewIndices | Known review indices | list of number |
| unknownIndices | Unknown indices | list of number |
{
"input": {
"observedMeasuredBodyPointSize": [
2,
5
],
"callerMeasuredBodyPointSizeLower": [
1,
1
],
"callerMeasuredBodyPointSizeUpper": [
3,
4
],
"knownMeasuredBodyPointSizeFlags": [
1,
0
]
},
"output": {
"signedKnownMargins": [
1,
0
],
"knownReviewIndices": [],
"unknownIndices": [
1
]
}
}Limitations and assumptions
The bands and applicability are supplied by the user. Unknown evidence is not a passing test, and the tool does not validate the source or the suitability of a criterion.
Missing required fields, unknown fields, wrong types, and violated calculation rules are input issues. Numeric values must be finite; nonfinite results are rejected. Evidence arrays must be dense, with no missing cells. Numeric observation lists allow at most 10,000 entries, subject to any smaller bounds stated above.
Alternative or Complementary methods
For a related review, use Large Text 18pt/24px Threshold Classifier: WCAG large-text size categories use CSS-equivalent point thresholds and distinguish bold from regular text. This screen evaluates only that size category, which is one input to a contrast review. For a complementary step, use Signage Letter Height From Viewing Distance: Sign-letter height and viewing distance together determine angular size. This tool inverts a supplied angular criterion using exact viewing geometry.
References
-
Minimum Body Size Accessibility pt Rule — tool.io
Similar or alternative tools
- Large Text 18pt/24px Threshold Classifier
WCAG large-text size categories use CSS-equivalent point thresholds and distinguish bold from regular text. This screen evaluates only that size category, which is one input to a contrast review.
- Signage Letter Height From Viewing Distance
Sign-letter height and viewing distance together determine angular size. This tool inverts a supplied angular criterion using exact viewing geometry.