Inline Code Monospace x-Height Match

Match inline-code and body actual x-height from independent font-unit metrics; not generic em conversion or assurance of equal stroke weight/baseline/cap height.

Description

Matching inline code to body x-height requires independent metrics from both fonts.

Matching inline code to body x-height requires independent metrics from both fonts. Equal x-height does not imply equal weight or baselines.^[1]

Enter all positive metrics and size. Return body visible x-height, matched code size and code/body ratio.

When to use Inline Code Monospace x-Height Match

Use Inline Code Monospace x-Height Match when you need to evaluate the supplied records under the calculation and evidence rules below. No font-file extraction, cap-height match or stroke/baseline equivalence is established.

Prepare measured font or typeset-layout values and the explicit design policy requested. For text or font bytes, use the supported syntax explained below.

How to use Inline Code Monospace x-Height Match and understand its results

Prepare measured font or typeset-layout values and the explicit design policy requested. For text or font bytes, use the supported syntax explained below.
Enter bodyFontSizePx, bodyXHeightUnits, bodyUnitsPerEm, codeXHeightUnits, codeUnitsPerEm using the field table and calculation rules, then run the tool.
Read bodyVisibleXHeightPx, matchedCodeFontSizePx, codeToBodySizeRatio. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
bodyFontSizePx	Body font size px	number	Required
bodyXHeightUnits	Body x height units	number	Required
bodyUnitsPerEm	Body units per em	number	Required
codeXHeightUnits	Code x height units	number	Required
codeUnitsPerEm	Code units per em	number	Required

Enter all positive metrics and size. Return body visible x-height, matched code size and code/body ratio.

bodyXHeight=bodySize×bodyXHeightUnits/bodyUPM; codeSize=bodyXHeight×codeUPM/codeXHeightUnits

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
bodyVisibleXHeightPx	Body visible x height px	number
matchedCodeFontSizePx	Matched code font size px	number
codeToBodySizeRatio	Code to body size ratio	number

json

{
  "input": {
    "bodyFontSizePx": 16,
    "bodyXHeightUnits": 500,
    "bodyUnitsPerEm": 1000,
    "codeXHeightUnits": 450,
    "codeUnitsPerEm": 1000
  },
  "output": {
    "bodyVisibleXHeightPx": 8,
    "matchedCodeFontSizePx": 17.77777777777778,
    "codeToBodySizeRatio": 1.1111111111111112
  }
}

Limitations and assumptions

No font-file extraction, cap-height match or stroke/baseline equivalence is established.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use x-Height Ratio From Font File: A font’s x-height ratio relates a native metric to units per em. Missing native metrics should be represented separately from measured outline height. For a complementary task, use Fallback Metrics Ascent/Descent Override: Font metrics overrides and size-adjust scaling interact. The requested percentages must account for scaling to reach the target layout metrics.

References

Inline Code Monospace x-Height Match — tool.io

Similar or alternative tools

x-Height Ratio From Font File
A font’s x-height ratio relates a native metric to units per em. Missing native metrics should be represented separately from measured outline height.
Fallback Metrics Ascent/Descent Override
Font metrics overrides and size-adjust scaling interact. The requested percentages must account for scaling to reach the target layout metrics.