Math Exponent Offset em
Convert caller chosen exponent baseline offset to pixels; does not infer OpenType MATH metrics.
Description
Convert a supplied superscript em offset to pixels.
A superscript's vertical offset can be parameterized in em units. This calculator converts a caller-selected signed offset to pixels at the declared em size.
When to use this tool
Convert a supplied superscript em offset to pixels. Use it when the input measurements and conventions below match the operation you need.
- Prepare emPx, callerOffsetEm, respecting the measurement basis and boundaries below.
- Compare the worked example with your intended operation before reusing its result.
How to use the tool and how it works
- Enter every field in the input table using the stated units and exact supported selector spelling where applicable.
- Run the tool. Correct input errors before interpreting an output.
- Read the result fields below; use accompanying flags and the stated sign, boundary or model convention when interpreting a number.
emPx must be positive. offsetPx is emPx times callerOffsetEm; a negative offset remains negative.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| emPx | Em px. Pixels. | Finite number; greater than zero |
| callerOffsetEm | Caller offset em. Em units. | Finite number |
| Output field | Interpretation |
|---|---|
| result | Object containing the following named result fields. |
| result.offsetPx | Offset px; use the stated units and sign convention. |
{
"input": {
"emPx": 16,
"callerOffsetEm": 0.3
},
"output": {
"result": {
"offsetPx": 4.8
}
}
}Limitations and assumptions
- The sign must be interpreted in the consuming layout's coordinate convention. The tool does not use a font's mathematical layout tables or position an exponent relative to actual glyphs.
- Every declared field is required and unexpected fields are rejected. Numeric inputs must be finite; input errors are distinct from a valid false result or an explicitly qualified output.
- Extremely large inputs and nonfinite or excessively large outputs are rejected. List positions reported by the tool use zero-based indices unless stated otherwise.
Alternative or Complementary methods
Compare the metric calculation with the intended font and rendered text. Font shaping and layout inspection are more appropriate when the task depends on actual glyph positions or reading conditions. Compare the scope of the nearby tools below before substituting one.
References
Similar or alternative tools
- hanging punctuation offset em
Hanging punctuation translates a glyph relative to a margin using its measured bearing and advance.
- baseline offset round to grid
Nearest baseline-grid multiple to a requested vertical offset in pixels.