# `hmtx`: Horizontal Metrics table

The `hmtx` table is an OpenType table.

class fontTools.ttLib.tables._h_m_t_x.table__h_m_t_x(tag=None)

  Bases: `DefaultTable`

  Horizontal Metrics table

  The `hmtx` table contains per-glyph metrics for the glyphs in a `glyf`, `CFF ``, or ``CFF2` table, as needed for horizontal text layout.

  See also https://learn.microsoft.com/en-us/typography/opentype/spec/hmtx

  headerTag = 'hhea'
  advanceName = 'width'
  sideBearingName = 'lsb'
  numberOfMetricsName = 'numberOfHMetrics'
  longMetricFormat = 'Hh'
  decompile(data, ttFont)
  compile(ttFont)
  toXML(writer, ttFont)
  fromXML(name, attrs, content, ttFont)
  mergeMap = {'metrics': <function sumDicts>, 'tableTag': <function equal>}
  subset_glyphs(s)