Baseboard Calculator

Estimate total baseboard length and number of boards, with waste and standard board lengths.

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Practical Guide

Baseboard Calculator: Fast, Accurate Linear Footage & Board Count

Use the baseboard calculator above to turn room dimensions into total linear feet/meters, the number of boards by standard lengths (8, 12, 16 ft or 2.4–4.8 m), and an optional cost estimate. This guide shows the exact steps, common pitfalls, and pro tips so your cut list is right the first time.

7–9 min read Updated November 10, 2025

Quick Start

  1. 1 In the calculator, pick your units (US/metric) and a method: Perimeter from room dimensions or Wall-by-wall lengths.
  2. 2 Enter dimensions for each room or wall run. Subtract door widths (not casing) and add closets/alcoves you plan to trim.
  3. 3 Choose available board length (8/10/12/16 ft or metric equivalents) and set a waste allowance (typ. 7–12%).
  4. 4 Optional: toggle shoe/quarter-round if you’ll install it—it generally matches the same linear footage.
  5. 5 Review outputs: Total LF/m, boards by length, and rounded “order” quantity. Export or copy to your cut list.

Tip: When in doubt, start with 10% waste. Bump to 12–15% for many short walls, lots of outside corners, or if you’re new to coping and scarf joints.

Watch-out: Subtract only clear openings (door widths). Do not subtract for inside corners, and include closet interiors, stair stringers, and island/peninsula backs if trimmed.

Variables & Symbols

  • L Room length
  • W Room width
  • P Room perimeter \(P=2(L+W)\)
  • O Sum of door openings
  • LF Linear footage \(LF=P-O\)
  • \\(\alpha\\) Waste fraction (e.g., 0.10 = 10%)
  • B_L Board length (e.g., 12 ft)
  • N Boards \(N=\lceil LF(1+\alpha)/B_L \rceil\)

Choosing Your Method

Method A — Perimeter from Room Dimensions

Fastest for rectangles or simple L-shapes where you can break spaces into rectangles.

  • Quick entry: just length and width per rectangle.
  • Great for preliminary pricing and square rooms.
  • Easy to sanity-check on plans.
  • Irregular spaces need multiple rectangles.
  • Door/window deductions must be applied manually.
Perimeter \(P=2(L+W)\) → Net \(LF=P-O\)

Method B — Wall-by-Wall Takeoff

Best for remodels and complex layouts where each run is unique.

  • Handles jogs, niches, bay windows, and alcoves cleanly.
  • Helps you plan joints and board lengths per wall.
  • More data entry if there are many short segments.
  • Requires careful field measurement notes.
Net \(LF=\sum \text{(wall runs)}-O\)

What Moves the Number

Total Perimeter

Perimeter dominates. Don’t forget closets, pantries, stair stringers, and island backs if trimmed.

Board Length Availability

Longer boards (12–16 ft) reduce joints and waste. Shorter boards (8–10 ft) may increase waste on long runs.

Waste Allowance

Account for miters, copes, scarf joints, defects, and color/grade matching. Typical: 7–12%, up to 15% for tricky work.

Corners & Technique

Coped inside corners hold tight with humidity; miters demand precise angles. More outside corners often → more waste.

Profile & Height

Taller or profiled baseboards don’t change length but can change waste (scarf joints, damage, grain selection).

Openings & Obstacles

Subtract door widths. Built-ins or cabinets usually eliminate base behind them; toe-kicks sometimes use shoe only.

Worked Examples

Example 1 — US (ft/in)

  • Main room: \(L=18\,\text{ft}\), \(W=14\,\text{ft}\)
  • Closet: \(6\times4\,\text{ft}\) (trim inside)
  • Openings: one 6-ft patio door + two 3-ft doors ⇒ \(O=12\,\text{ft}\)
  • Board length: \(B_L=12\,\text{ft}\)
  • Waste: \(\alpha=10\% = 0.10\)
1
Main perimeter: \[P_{main}=2(L+W)=2(18+14)=64\,\text{ft}\]
2
Closet perimeter: \[P_{closet}=2(6+4)=20\,\text{ft}\]
3
Net linear feet (before waste): \[LF=(64+20)-O=84-12=72\,\text{ft}\]
4
Add waste: \[LF_w=LF(1+\alpha)=72(1.10)=79.2\,\text{ft}\Rightarrow \approx 80\,\text{ft}\]
5
Boards needed (12-ft): \[N=\left\lceil \dfrac{80}{12} \right\rceil=\lceil 6.67 \rceil=7\] (With 16-ft boards: \(\lceil 80/16\rceil=5\))

Example 2 — Metric (m/mm)

  • Room: \(L=5.0\,\text{m}\), \(W=4.2\,\text{m}\)
  • Openings: two 0.9 m doors ⇒ \(O=1.8\,\text{m}\)
  • Board length: \(B_L=3.6\,\text{m}\)
  • Waste: \(\alpha=8\%\)
1
Perimeter: \[P=2(5.0+4.2)=18.4\,\text{m}\]
2
Net LF: \[LF=P-O=18.4-1.8=16.6\,\text{m}\]
3
With waste: \[LF_w=16.6\times1.08=17.928\,\text{m}\approx17.93\,\text{m}\]
4
Boards (3.6 m): \[N=\left\lceil\dfrac{17.93}{3.6}\right\rceil=\lceil4.98\rceil=5\]

Rounding: round up boards to whole pieces and consider ordering one extra board per room for defects and future repairs.

Profiles, Corners & Variations

Material, profile, and corner strategy don’t change the perimeter math, but they do change waste, time, finish quality, and cost.

VariationImpact on Waste/TimeNotes
MDF (primed)Low–moderate wasteStable and paint-ready; avoid wet areas (bath, mudroom). Dings easily during handling.
Finger-jointed pine (paint)Low wasteEconomical; joints disappear under paint. Good for most interiors.
Hardwood (oak/poplar)Moderate wasteStronger; stain-grade. Select grain and color; cut out defects → extra waste.
PVC/PolymerLow wasteBest for moisture. Use PVC cement/adhesive; expansion gaps per mfr.
Tall profiles (≥5.25″)ModerateMore scarf joints on long runs; pre-prime/paint end cuts to prevent swelling.
Coped inside cornersModerate time, tighter seamsResists seasonal gapping; learn the coping cut. Miters are faster but less forgiving.
Board length: 8/10/12/16 ftLonger = less wasteUse the longest you can transport/handle; plan joints over studs.
Shoe/quarter-round+5% waste (typ.)Use where floors aren’t perfectly flush or when hiding small gaps.
  • Locate scarf joints over studs; back-bevel 10–15° for tight seams.
  • Pre-paint or at least prime profiles before install; touch up after caulk.
  • Scribe to wavy floors for a tight line; don’t rely on caulk alone.
  • In wet rooms, choose PVC/polymer or keep MDF off the floor with a shoe.

Buying, Logistics & Practicalities

Selection Criteria

  • Look & height: For 8-ft ceilings, common heights are 3¼–5¼″. For 9–10-ft ceilings, 5¼–7¼″ looks proportional.
  • Finish: Painted → MDF/finger-jointed pine; Stained → hardwood.
  • Moisture: Baths, mudrooms, basements → favor PVC or hardwood; avoid MDF in splash zones.
  • Handling: If you’re solo, 12-ft boards are typically manageable; 16-ft may need a helper.

Logistics & Install

  • Acclimate wood in the space for 24–48 hours.
  • Snap a level line in older homes; scribe where floors vary.
  • Fasten at studs (or 16″ o.c.) with 15–18 ga nails; glue outside miters.
  • Caulk top edge lightly; don’t caulk the floor joint.
  • Pre-paint one coat; final coat after filling/caulk.

Sanity Checks

  • Does total LF/m match a quick perimeter estimate?
  • Do you have enough long boards to minimize scarf joints?
  • Did you include closets, stair stringers, and returns at door casings?
  • Do your waste and extra boards cover defects/warping?

Codes: Baseboard itself isn’t a code item, but local trim details around stairs and fire-rated doors may impose constraints. Follow manufacturer and local best practices.

Frequently Asked Questions

Do I subtract doors and openings from baseboard length?
Yes—subtract the clear width of doors (e.g., 30″, 36″). Don’t subtract for inside corners, and don’t subtract window openings unless there’s no baseboard run beneath a low window seat or built-in.
How much waste should I include?
Most projects use 7–12%. Go to 12–15% for many short pieces, numerous outside corners, or if you need color/grain matching on stain-grade boards.
What are standard baseboard lengths?
Common stock lengths are 8, 10, 12, and 16 ft (metric: 2.4–4.8 m). Choose the longest you can transport and handle to reduce joints.
How tall should my baseboards be?
A quick guideline is roughly 1/12 to 1/10 of ceiling height. For 8-ft ceilings, 3¼–5¼″ is typical; for 9–10 ft, 5¼–7¼″ feels proportional.
Should I add shoe or quarter-round molding?
Add it when floors aren’t perfectly flat or when you want a crisp paintable line. Linear footage is about the same as the baseboard run; include ~5% extra waste.
Is coping better than mitering inside corners?
Coping takes longer to learn but resists seasonal gaps and looks tighter over time. Miters are fine when walls are square and stable, but they can open if angles or humidity shift.
How do I estimate boards for stairs?
Measure along the stringer (the sloped edge). A quick estimate is the diagonal per tread: \( \sqrt{\text{rise}^2+\text{run}^2} \times \text{tread count} \), plus landings and returns.
How do I estimate cost?
Multiply total LF/m (with waste) by your price per foot/meter, add fasteners/adhesive/caulk, and paint or finishing costs. The calculator can output a per-foot cost if you supply it.
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