komorebi/docs/common-workflows/layout-ratios.md

Layout Ratios

With komorebi you can customize the split ratios for various layouts using column_ratios and row_ratios in the layout_options configuration.

Before and After

BSP layout example:

Before (default 50/50 splits):

After (with column_ratios: [0.7] and row_ratios: [0.6]):

Configuration

{
  "monitors": [
    {
      "workspaces": [
        {
          "name": "main",
          "layout_options": {
            "column_ratios": [0.3, 0.4],
            "row_ratios": [0.4, 0.3]
          }
        }
      ]
    }
  ]
}

You can specify up to 5 ratio values (defined by MAX_RATIOS constant). Each value should be between 0.1 and 0.9 (defined by MIN_RATIO and MAX_RATIO constants). Values outside this range are automatically clamped. Columns or rows without a specified ratio will share the remaining space equally.

Usage by Layout

Layout	column_ratios	row_ratios
Columns	Width of each column	-
Rows	-	Height of each row
Grid	Width of each column (rows are equal height)	-
BSP	[0] as horizontal split ratio	[0] as vertical split ratio
VerticalStack	[0] as primary column width	Stack row heights
RightMainVerticalStack	[0] as primary column width	Stack row heights
HorizontalStack	Stack column widths	[0] as primary row height
UltrawideVerticalStack	[0] center, [1] left column	Tertiary stack row heights

Examples

Columns Layout with Custom Widths

Create 3 columns with 30%, 40%, and 30% widths:

{
  "layout_options": {
    "column_ratios": [0.3, 0.4]
  }
}

Note: The third column automatically gets the remaining 30%.

Rows Layout with Custom Heights

Create 3 rows with 20%, 50%, and 30% heights:

{
  "layout_options": {
    "row_ratios": [0.2, 0.5]
  }
}

Note: The third row automatically gets the remaining 30%.

Grid Layout with Custom Column Widths

Grid with custom column widths (rows within each column are always equal height):

{
  "layout_options": {
    "column_ratios": [0.4, 0.6]
  }
}

Note: The Grid layout only supports column_ratios. Rows within each column are always divided equally because the number of rows per column varies dynamically based on window count.

VerticalStack with Custom Ratios

Primary column takes 60% width, and the stack rows are split 30%/70%:

{
  "layout_options": {
    "column_ratios": [0.6],
    "row_ratios": [0.3]
  }
}

Note: The second row automatically gets the remaining 70%.

HorizontalStack with Custom Ratios

Primary row takes 70% height, and the stack columns are split 40%/60%:

{
  "layout_options": {
    "row_ratios": [0.7],
    "column_ratios": [0.4]
  }
}

Note: The second column automatically gets the remaining 60%.

UltrawideVerticalStack with Custom Ratios

Center column at 50%, left column at 25% (remaining 25% goes to tertiary stack), with tertiary rows split 40%/60%:

{
  "layout_options": {
    "column_ratios": [0.5, 0.25],
    "row_ratios": [0.4]
  }
}

Note: The second row automatically gets the remaining 60%.

BSP Layout with Custom Split Ratios

Use separate ratios for horizontal (left/right) and vertical (top/bottom) splits:

{
  "layout_options": {
    "column_ratios": [0.6],
    "row_ratios": [0.3]
  }
}

• column_ratios[0]: Controls all horizontal splits (left window gets 60%, right gets 40%)
• row_ratios[0]: Controls all vertical splits (top window gets 30%, bottom gets 70%)

Note: BSP only uses the first value ([0]) from each ratio array. This single ratio is applied consistently to all splits of that type throughout the layout. Additional values in the arrays are ignored.

Notes

• Ratios are clamped between 0.1 and 0.9 (prevents zero-sized windows and ensures space for other windows)
• Default ratio is 0.5 (50%) when not specified, except for UltrawideVerticalStack secondary column which defaults to 0.25 (25%)
• Ratios are applied progressively - a ratio is only used when there are more windows to place after the current one
• The last window always takes the remaining space, regardless of defined ratios
• Ratios that would sum to 100% or more are automatically truncated at config load time to ensure there's always space for additional windows
• Unspecified ratios default to sharing the remaining space equally
• You only need to specify the ratios you want to customize; trailing values can be omitted

Progressive Ratio Behavior

Ratios are applied progressively as windows are added. For example, with row_ratios: [0.3, 0.5] in a VerticalStack:

Windows in Stack	Row Heights
1	100%
2	30%, 70% (remainder)
3	30%, 50%, 20% (remainder)
4	30%, 50%, 10%, 10% (remainder split equally)
5	30%, 50%, 6.67%, 6.67%, 6.67%

Automatic Ratio Truncation

When ratios sum to 100% (or more), they are automatically truncated at config load time.

For example, if you configure column_ratios: [0.4, 0.3, 0.3] (sums to 100%), the last ratio (0.3) is automatically removed, resulting in effectively [0.4, 0.3]. This ensures there's always remaining space for the last window.

Configured Ratios	Effective Ratios	Reason
[0.3, 0.4]	[0.3, 0.4]	Sum is 0.7, below 1.0
[0.4, 0.3, 0.3]	[0.4, 0.3]	Sum would be 1.0, last ratio truncated
[0.5, 0.5]	[0.5]	Sum would be 1.0, last ratio truncated
[0.6, 0.5]	[0.6]	Sum would exceed 1.0, last ratio truncated

This ensures the layout always fills 100% of the available space and new windows are never placed outside the visible area.