Baseboard Casing Calculator

Purpose and model boundary

This calculator estimates the baseboard and the door and window casing to order for the rooms of a floor plan you draw. You draw the outline, the interior walls, the windows and the doors, set one wall height for the plan and each opening's height, and the spreadsheet returns the baseboard run, the baseboard sticks to order, the casing length and the casing sticks to order, room by room, in sticks of the stock length you buy. It does not estimate crown molding, chair rail, window stools or aprons, and it does not price anything or estimate labour.

Inputs and units

The drawing is the first input. The drawing tool finds the rooms and writes one row per room (its ID, floor area and enclosing-wall length), one row per wall side of every room, and one row per window and per door with its width and the room it belongs to. A wall between two rooms is listed once for each room, and a free-standing partition twice. The outline is also sent as its corner points, and up to five islands or columns inside the floor as exclusions. Each exclusion can carry a height, set by double-clicking it on the drawing (blank is full height); it is carried for the drawing and its 3D view only, and no figure reads it, since an island or column gets no baseboard whatever its height.

The heights are set on the drawing or in the tables under it: one wall height for the whole plan, set with the drawing's Wall height button, each door's height, and each window's height and sill height. Lengths and heights are in feet under US and metres under Metric, never inches. Each unit system keeps its own opening heights and its own stock length, which are never converted into each other; the wall height is one physical height and converts exactly on a switch (8 ft is 2.4384 m). After a switch, or when a worked example loads, an opening with no height in the current system gets the drawing's default for that system: a door 6 ft 8 in or 2.03 m, no higher than the wall, and a window 4 ft or 1.20 m on a 3 ft or 0.90 m sill, the sill lowered as needed so the window fits below the wall. The 3D view shows the same inputs and changes nothing.

The inputs beside the drawing are:

• Stock length: the length of one stick of baseboard and casing, 12 ft under US and 3.6 m under Metric by default. Each system has its own value; common US stock is 8, 12 and 16 ft.
• Allow splicing: No cuts each wall side from its own sticks; Yes joins offcuts so each room's floor run is bought as one length.
• Trim waste: extra for cuts, miters and defects, 10% by default, applied once.
• Casing: Yes counts door and window casing; No counts baseboard only.

The stock length, splicing and waste defaults are the worked examples' figures; replace them with your supplier's stock and your own allowance.

Governing relationships

For each room, the wall run is the sum of its wall rows, and the floor run is the wall run less the widths of the doors that open into it:

Floor run = wall run − door widths

Baseboard run = sum of every room's floor run

With splicing off, each room's door widths come off its sides longest first, and each side is then cut from whole sticks:

Sticks for a side = (side length − door width taken off it) ÷ stock length, rounded up to a whole stick

With splicing on, each room takes its floor run in whole sticks:

Sticks for a room = floor run ÷ stock length, rounded up to a whole stick

Baseboard sticks to order = sticks before waste × (1 + waste), rounded up

With casing on, each window and door takes two legs of its height and a head of its width:

Casing for an opening = 2 × height + width

Casing sticks to order = casing length × (1 + waste) ÷ stock length, rounded up

Waste applies once: to the baseboard stick count, and to the casing length before it is counted in sticks. The wall height and the sill heights enter no quantity; they are read only by the checks that keep every opening physically possible.

Calculation sequence

1. The spreadsheet sums each room's wall rows into its wall run and subtracts the widths of the doors that open into the room to give its floor run, then adds the floor runs into the baseboard run.
2. It counts the sticks per wall side (splicing off) or per room (splicing on). Every division is rounded to six decimals before it is rounded up, so a figure that is whole on paper stays whole: a 7.2 m floor run in 3.6 m sticks is exactly 2 sticks, not 3.
3. It adds the waste to the stick count and rounds up.
4. With casing on, it adds two legs of each opening's height and a head of its width into the casing length, adds the waste and counts it in whole sticks.

The default plan works through as follows: one 20 by 15 ft room with no openings, walls 20, 15, 20 and 15 ft, gives a 70 ft baseboard run. With 12 ft stock and splicing off, each 20 ft side takes 20/12 → 2 sticks and each 15 ft side 15/12 → 2, so the two pairs of sides take 8 sticks; with 10% waste, 8 × 1.1 = 8.8 → 9 sticks to order. There are no openings, so the casing is 0. Under Metric, a plan's runs are in metres and its sticks are counted in 3.6 m stock.

An opening's real height decides its casing: a 3 ft door 6 ft 8 in high takes 2 × 6 ft 8 in + 3 ft = 16 ft 4 in (16.33 ft) of casing; at 8 ft high it takes 19 ft.

Outputs and interpretation

• Baseboard run: every room's wall run less the width of the doors that open into it, in feet or metres.
• Baseboard sticks to order and baseboard sticks before waste: whole sticks of the stock length.
• Casing length: two legs of each opening's height plus a head of its width, in feet or metres.
• Casing sticks to order: the casing length plus waste, in whole sticks.
• The floor's net area, gross area and the area of each island or column, from the drawing.
• By room: each room's wall run, the door openings taken off, its floor run, its baseboard sticks before waste and its casing, under headings in the unit the drawing was sent in.

Validation and status logic

The status reads OK, or NOT VALID with what to fix. While it is NOT VALID every quantity reads zero and the By room rows are blank. The first problem found is reported, in this order:

1. NOT VALID: choose US or Metric
2. NOT VALID: draw at least three outline points
3. NOT VALID: every outline point needs both coordinates
4. NOT VALID: every point of exclusion 1 needs both coordinates
5. NOT VALID: every point of exclusion 2 needs both coordinates
6. NOT VALID: every point of exclusion 3 needs both coordinates
7. NOT VALID: every point of exclusion 4 needs both coordinates
8. NOT VALID: every point of exclusion 5 needs both coordinates
9. NOT VALID: each exclusion needs zero or at least three complete points
10. NOT VALID: outline and exclusion points must fill consecutive rows, with no blank row between them
11. NOT VALID: the floor outline encloses no area
12. NOT VALID: the exclusions leave no floor area
13. NOT VALID: room, wall, window and door rows must be complete, with lengths above zero and no negative area, and fill consecutive rows with no blank row between them
14. NOT VALID: every room must be listed once, and every wall, window and door must belong to a listed room
15. NOT VALID: the walls listed do not go all the way round every room and the outline drawn
16. NOT VALID: wall, window and door IDs must each be listed once, and no ID or room ID may contain *, ? or ~ or begin with <, > or =
17. NOT VALID: the doors and windows in a room are wider than its walls
18. NOT VALID: stock length must be greater than zero
19. NOT VALID: enter a trim waste between 0% and 100%
20. NOT VALID: choose Yes or No for splicing
21. NOT VALID: choose Yes or No for casing
22. NOT VALID: the wall height must be from 6 to 20 ft (US) or from 1.80 to 6.00 m (Metric)
23. NOT VALID: every window needs a height of at least 1 ft (US) or 0.30 m (Metric)
24. NOT VALID: every window needs a sill height of zero or more
25. NOT VALID: every door needs a height of at least 5 ft (US) or 1.50 m (Metric)
26. NOT VALID: a window or door reaches above the wall height
27. NOT VALID: an exclusion height must be greater than zero; leave it blank for full height
28. NOT VALID: an exclusion height is given for an exclusion that is not drawn

The height limits are the drawing tool's own (a wall of 6 to 20 ft or 1.80 to 6.00 m, a door of at least 5 ft or 1.50 m, a window of at least 1 ft or 0.30 m, and every opening below the wall): the spreadsheet holds a direct caller to the drawing tool's range for each unit system (items 22 to 26), and the page narrows the wall and the openings to the ranges valid in both systems. They are checked with casing on or off. On the page, the Wall height editor accepts only heights that stay valid in both systems after a switch (6 ft to 6.00 m), the drawing asks for a window at least 1 ft (0.3048 m) and a door at least 5 ft (1.524 m) tall in both systems, so in Metric it refuses a 0.30 m window or a 1.50 m door that the spreadsheet alone would take, and every new opening starts with the drawing's default heights. The wall lengths and the door and window widths are the drawing tool's rows; the spreadsheet re-measures only the outline from its points and checks the rows against it.

Assumptions and limitations

• With splicing off, the door widths come off each room's longest sides first, because the tables do not say which side a door is on. Against cutting each side on site this can be one stick per door too few or too many: a 13 by 10 ft room with a 3 ft door on a 10 ft side counts 5 where the site needs 6; a 16 by 13 ft room with a 1.5 ft door on a 13 ft side counts 8 where 7 do.
• An interior door is listed once, for the room it opens into: the other room's baseboard is long by one door width, and its casing is short by two heights and a width per interior door.
• Casing is counted as one pooled length; cutting it leg by leg can need one more stick than shown when a leg is longer than half a stick.
• No baseboard is counted round an island or column.
• The wall lengths and the door and window widths are the drawing tool's rows; the spreadsheet re-measures only the outline from its points and checks the rows against it.
• The height limits are the drawing tool's, not a building code; check local code for egress and door requirements.
• A window drawn down to the floor (sill 0) is not taken off the baseboard, so the baseboard is long by that window's width; draw a floor-length opening as a door.
• One wall height applies to the whole plan; per-room heights are not used.
• Nothing is saved between visits. Export keeps the drawing but not the heights, and the room areas and enclosing lengths come from the drawing tool's room detection.

Restrictions and non-computing states

The spreadsheet computes nothing while the status is NOT VALID: every quantity reads zero and the By room rows are blank. Edits on the page stay local until Calculate is pressed.

Errors and warnings

Each NOT VALID line above names the input to fix. A height outside the drawing's limits, a blank opening height or a blank sill on a window that has a height is refused even with casing off, because the opening must still fit the wall.

Sources and further reading

• National Institute of Standards and Technology, Guide for the Use of the International System of Units (SI), NIST Special Publication 811, Appendix B.8. nist.gov. The foot is exactly 0.3048 m, behind the drawing's two systems: lengths in feet under US and metres under Metric, each system's typed values its own.
• Gerald E. Sherwood and Robert C. Stroh, Wood-Frame House Construction, USDA Forest Service, Agriculture Handbook 73 (revised 1989). archive.org. Chapter 6, "Interior doors" (p. 187): the standard door height is 6 ft 8 in, the drawing's default door height under US. Chapter 7, "Interior trim" (p. 192): door and window casing as side and head casing joined at the corners, the two legs and a head this calculator counts. Chapter 7, "Base molding and base shoe" (p. 195): base molding as the finish between the wall and the floor.
• Jay Abramson, College Algebra 2e, OpenStax, section 2.1, "Using the Distance Formula". openstax.org. The distance formula, which the spreadsheet uses to re-measure the outline's perimeter from its points.
• Eric W. Weisstein, "Polygon Area," MathWorld, Wolfram Research. mathworld.wolfram.com. The shoelace formula behind the gross, exclusion and net areas.

The stock length, splicing and waste defaults are the worked examples' figures, and the height defaults and limits are the drawing tool's; these sources describe units, geometry and practice and certify no particular result.