Trim Molding
Estimate baseboard and crown molding length for a room.
About Trim Molding
The room perimeter runs the full wall base for baseboard, minus the door opening, while crown molding covers the full perimeter. The total depends on which trim type is selected. Molding is sold by the linear foot, so perimeter math converts a room directly into the length of trim to buy.
Formula
Trim Molding
Baseboard = perimeter - door opening; crown = perimeter
- perimeter
- Sum of all room wall lengths
Worked example
With the default values below, Trim Molding returns Baseboard of 49. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Room width
- 12 ft
- Room length
- 14 ft
- Door opening
- 32 in
- Trim typeone of Baseboard, Crown, Both
- Both
Results
- Baseboard
- 49 ft
- Crown
- 52 ft
- Total Trim
- 101 ft
Step by step
- 1Values used
- 2Trim Molding
- 3Baseboard= 49 ft
- 4Crown= 52 ft
- 5Total Trim= 101 ft
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Trim Molding calculated?
Baseboard = perimeter - door opening; crown = perimeter The room perimeter runs the full wall base for baseboard, minus the door opening, while crown molding covers the full perimeter. The total depends on which trim type is selected.
Why does Trim Molding matter?
Molding is sold by the linear foot, so perimeter math converts a room directly into the length of trim to buy.
What values do I need to enter?
This calculator takes 4 inputs: Room width, Room length, Door opening, Trim type. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.