Fix Missing Metrics for New Glyphs in FontForge

When you add new glyphs or import vector outlines into FontForge, they often lack proper advance widths and side bearings, causing characters to overlap or display incorrectly. This guide explains how to restore and configure missing metric values for newly created glyphs using FontForge’s manual input options, interactive Metrics View, and automated width tools.

Why Metrics Go Missing

When drawing a glyph from scratch or pasting an SVG/EPS outline into an empty slot, FontForge typically defaults the horizontal advance width to zero or to the font’s default width without adjusting the Left Side Bearing (LSB) or Right Side Bearing (RSB). Without defined bearings, the glyph has no spacing boundaries relative to neighboring characters.

Method 1: Using the Metrics Window

The interactive Metrics Window is the most intuitive way to visually inspect and assign metric values alongside reference characters.

  1. Select your newly added glyph in the font view.
  2. Hold Shift and select a few standard reference glyphs (such as "H", "O", or "n") to compare spacing.
  3. Go to the top menu and select Metrics > Open Metrics Window (or press Ctrl + K / Cmd + K).
  4. In the table below the visual preview, locate your new glyph's column.
  5. Click directly into the LBearing, RBearing, or Width fields to type specific numerical values.
  6. Alternatively, click and drag the vertical boundary lines in the preview pane to set the LSB and advance width interactively.

Method 2: Setting Metric Values via Glyph Info

If you already know the exact units you need for advance width:

  1. Right-click the new glyph in the main grid view and select Glyph Info.
  2. Navigate to the Horizontal tab on the left sidebar.
  3. Check the Set Width box and enter your desired advance width in font units.
  4. Click OK to save the changes.

Method 3: Using Auto Width

For bulk adjustments or quick estimation based on existing glyph standards, FontForge can automatically calculate side bearings based on the contours of the artwork.

  1. Select the newly created glyphs in the font view window.
  2. Navigate to Metrics in the top menu bar.
  3. Select Auto Width....
  4. In the dialog, set a target spacing value (this specifies the optical distance between adjacent glyphs).
  5. Click OK. FontForge will calculate appropriate LSB and RSB values according to the shape of each outline.

Method 4: Correcting Transform Offsets

If a glyph appears outside its designated bounding box:

  1. Double-click the glyph to enter the Outline Editing window.
  2. Press Ctrl + A to select all points.
  3. Go to Element > Transformations > Transform.
  4. Choose Move to reposition the artwork so the leftmost point aligns properly with the origin axis (x = 0), establishing a clean baseline for the Left Side Bearing.
  5. Close the outline window and adjust the advance width line manually or via the Metrics menu.