Baseboard Calculator
Linear feet of baseboard (skirting) for a room minus door openings, converted to 8, 12, 14 or 16 ft pieces with waste, nails and caulk.
Your estimate
5 × 12 ft
Baseboard pieces (incl. 10% waste)
- Linear footage
- 49 ft net, 53.9 ft with waste
- Wall perimeter
- 52 ft
- Door openings removed
- 1 × 36 in = 3 ft
- Scarf joints on long walls
- 2
- Inside corners
- 4
- 2 walls are longer than one 12 ft piece and need a scarf joint — longer stock avoids it.
Show the math
- Perimeter = 2 × (14 ft + 12 ft) = 52 ft
- − 1 door × 36 in = 49 ft
- × (1 + 10%) = 53.9 ft
- ÷ 12 ft per piece → 5 pieces
Shopping list & cost
| Item | Spec | Qty | Cost |
|---|---|---|---|
| Baseboard | 12 ft lengths | 5 pcs (60 ft) | — |
| Finish nails | 2 in 16 ga, 2 per stud | ≈ 74 | — |
| Paintable caulk | ⅛ in bead along the top edge | 1 tube | — |
Prices are what you enter under Advanced options. Estimates only — check stock and pricing with your supplier.
Quick answer A 14 × 12 ft room with one door needs 49 ft of baseboard after removing the 36 in opening — 5 × 12 ft pieces with 10% waste. A 4.2 × 3.6 m room needs 4 × 4.2 m lengths of skirting. Linear feet = room perimeter − door openings; pieces = linear feet × 1.10 ÷ stock length, rounded up.
Method & assumptions
Perimeter = 2 × (Length + Width) Linear feet = Perimeter − Doors × Opening width Pieces = Linear feet × (1 + waste %) ÷ Stock length, rounded up
- Opening width
- door width plus both casings; 36 in (90 cm) default
- Stock length
- commonly 8, 12, 14 or 16 ft; 2.4, 4.2 or 5.4 m
- Waste
- miters, copes and offcuts too short to use
Assumptions & limits
- Rectangular rooms have four inside corners; outside corners (bump-outs, columns) add cuts — raise waste to 15% or enter total wall length.
- Walls longer than one piece need a scarf joint; the calculator counts them for room mode.
- Nails: two per stud at 16 in centers (about 1.5 per foot). Caulk: one 10 oz tube lays roughly 100 ft of ⅛ in bead along the top edge.
Rounding: purchase quantities are always rounded up to whole units as sold. See our methodology.
Diagram
How to use this calculator
- Measure the room length and width, or switch to "Total wall length" and add up every wall that gets trim, including closets and bump-outs.
- Count the door openings. Baseboard stops at the door casing, so each opening removes the door width plus both casings — about 36 in for a 30–32 in door.
- Choose the stock length. Longer pieces mean fewer joints on long walls.
- Keep 10% waste for simple rooms and 15% for rooms with many corners.
- Add shoe molding or quarter round if you are installing a floating floor.
Worked examples
Imperial: 12 × 11 ft bedroom, entry + closet door, 16 ft stock
- Perimeter = 46 ft; − 2 × 3 ft = 40 ft
- × 1.10 = 44 ft ÷ 16 = 2.75 → 3 pieces (48 ft)
Metric: open-plan walls totalling 22 m, 3 doors, 4.2 m skirting
- 22 − 3 × 0.9 = 19.3 m
- × 1.10 = 21.2 m ÷ 4.2 = 5.05 → 6 lengths
In depth: baseboard planning notes
Measuring trim the way it is installed
Baseboard runs along the bottom of every wall and stops at door casings, so the footage is the perimeter less the openings. For a rectangle that is 2 × (length + width); for anything more complex, add the walls one by one, including closets, bump-outs, the sides of a fireplace and the short returns beside a door. The opening to subtract is the door width plus both casings — about 36 in for a typical 30–32 in interior door. Doorways without doors (cased openings) still break the run.
Converting footage to pieces is where 10% waste comes in. Every inside corner is coped or mitered, every outside corner mitered, and the offcuts from the end of each wall are often too short to use. Long walls are the other trap: a 14 ft wall can't be covered with one 12 ft piece, so you need a scarf joint — two 45° cuts overlapping over a stud — which costs a little length and looks best away from the room's focal point. Buying 16 ft stock avoids most of them, if you can get it home.
Shoe molding, nails and finishing
Floating floors need an expansion gap at the walls, and either the baseboard or a shoe molding (quarter round) covers it. If the baseboard goes on after the floor, it may cover the gap alone; if the baseboard is already there, add shoe molding at the same footage and nail it to the baseboard, not the floor, so the floor can move. With carpet, baseboard is usually installed ⅜–½ in above the subfloor so the carpet can tuck under it.
Use 2 in finish nails, 16 or 15 gauge, two per stud — one low into the bottom plate and one higher into the stud — which works out to about 1.5 nails per foot. Pre-prime and paint the pieces before installing; afterwards you only fill nail holes and run a thin bead of paintable caulk along the top edge, which closes the small gaps left by wavy walls. One 10 oz tube lays roughly 100 ft of ⅛ in bead. In the UK and Australia, skirting is often glued with grab adhesive on masonry walls rather than nailed.
Reference table
| Room | Linear feet · 12 ft pieces |
|---|---|
| 10 × 10 ft | 37 ft · 4 |
| 12 × 12 ft | 45 ft · 5 |
| 14 × 12 ft | 49 ft · 5 |
| 16 × 14 ft | 57 ft · 6 |
| 20 × 15 ft | 67 ft · 7 |
Key facts
- Inside corners
- coped for a tight joint (or mitered on MDF)
- Outside corners
- mitered at 45°
- Long walls
- scarf joint (overlapping 45° cuts) over a stud
- Nails
- 2 in 16 ga or 15 ga finish nails, two per stud
Tips & common mistakes
- Buy the longest stock you can transport — every joint you avoid is one less to fill and sand.
- Cope inside corners on wood baseboard; miters open up as the wood shrinks seasonally.
- Install baseboard after the flooring (or with a gap above carpet) so it sits on the finished surface.
- Prime and paint the pieces before installing; then you only need to fill nail holes and caulk the top edge.
Frequently asked questions
How do I calculate linear feet of baseboard?
Add the length of every wall (or 2 × (length + width) for a rectangular room), then subtract the width of each door opening. A 12 × 12 ft room with one door needs 48 − 3 = 45 linear feet.
How many pieces of baseboard do I need for a 12 × 12 room?
About 45 ft after one door; with 10% waste that is 49.5 ft — five 12 ft pieces, four 16 ft pieces, or seven 8 ft pieces.
How much extra baseboard should I buy?
10% for simple rectangular rooms, 15% for rooms with many outside corners, angled walls or short wall sections, plus one spare piece if you are new to coping.
Do I subtract doors when measuring baseboard?
Yes. Baseboard stops at the door casing, so subtract the full opening including casings — about 36 in for a standard interior door.
Do I need shoe molding or quarter round?
Usually with floating floors (laminate, LVP, engineered wood) to cover the expansion gap, unless the baseboard is installed after the floor and covers the gap itself. It is the same linear footage as the baseboard.
Sources
- Metrie – Interior Moulding & Trim profile guide 2025 (PDF, dealer-hosted) — accessed : “BASEBOARD – e.g. MFP645 9/16" x 5" x 16'; MFP745 7/16" x 4" x 16'”
- Fine Homebuilding – coping inside corners on baseboard — general reference — not cited for a specific figure
- This Old House – how to install baseboard — general reference — not cited for a specific figure
- NIST – unit conversion factors — general reference — not cited for a specific figure
Default values (yields, coverage rates and densities) are typical figures from manufacturer literature. Always check the label on the product you buy.
Related calculators
- Crown Molding CalculatorHow much crown molding do you need? Pieces of 8, 12 or 16 ft stock counted wall by wall, with splices, cutting allowance and a spare.
- Flooring CalculatorCalculate boxes of vinyl plank, hardwood or engineered flooring, including a 12×12 room, with layout waste, underlay and baseboard.
- Laminate Flooring CalculatorLaminate-specific estimate: boxes of planks, underlayment rolls and vapor barrier, quarter round, transitions, expansion gap and last-row width.
Learn more in our guides
Method, waste and worked examples: Flooring area: waste, boxes and roll width.
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DIYCalcLab. “Baseboard Calculator.” Oct 19, 2026. https://diycalclab.com/flooring/baseboard-calculator/
Estimates only. Verify quantities with your supplier and local building codes. For structural, electrical or safety-critical work, consult a licensed professional. Full disclaimer.