Perimeter = 2 × (length + width) — and why baseboard and crown deduct differently

A rectangle’s perimeter is 2 × (length + width): a 14 × 12 ft room is 52 LF. The deduction depends on the trade — baseboard skips a 3 ft doorway (52 − 3 = 49 LF), but crown runs over it and keeps the full 52 LF.

A room shown in plan, 14 feet by 12 feet, with the perimeter figured as 2 times 14 plus 12, which is 52 linear feet of edge. A 3-foot door opening is drawn in the bottom wall. Two take-offs come from the same 52-foot loop. Baseboard subtracts the doorway, because no trim runs across the opening, so 52 minus 3 leaves 49 linear feet. Crown or cornice runs continuously over the door and is not deducted, so it keeps the full 52 linear feet. The perimeter feeds baseboard, crown, chair rail, fence, gutter, and deck rail — subtract door openings for base, but keep the whole loop for crown. — Source: Perimeter = 2 × (L + W); openings deducted for base, not crown (src/lib/calculators/linearFeet.js)

Use this diagram free on your site — grab the embed codeGet the code

What this diagram shows

A room shown in plan, 14 feet by 12 feet, with the perimeter figured as 2 times 14 plus 12, which is 52 linear feet of edge. A 3-foot door opening is drawn in the bottom wall. Two take-offs come from the same 52-foot loop. Baseboard subtracts the doorway, because no trim runs across the opening, so 52 minus 3 leaves 49 linear feet. Crown or cornice runs continuously over the door and is not deducted, so it keeps the full 52 linear feet. The perimeter feeds baseboard, crown, chair rail, fence, gutter, and deck rail — subtract door openings for base, but keep the whole loop for crown.

Use this diagram — free

You're welcome to use this diagram on your own site, blog, handout, or lesson at no cost. The only condition is a visible credit link back to the source page. Copy the snippet below and paste it into your page — the credit is already included.

Embed code (HTML)

<figure style="margin:0;max-width:800px">
  <a href="https://remodelcalculators.com/construction-diagrams/linear-feet-perimeter" target="_blank" rel="noopener">
    <img src="https://remodelcalculators.com/api/figure-embed/linear-feet-perimeter" alt="A room shown in plan, 14 feet by 12 feet, with the perimeter figured as 2 times 14 plus 12, which is 52 linear feet of edge. A 3-foot door opening is drawn in the bottom wall. Two take-offs come from the same 52-foot loop. Baseboard subtracts the doorway, because no trim runs across the opening, so 52 minus 3 leaves 49 linear feet. Crown or cornice runs continuously over the door and is not deducted, so it keeps the full 52 linear feet. The perimeter feeds baseboard, crown, chair rail, fence, gutter, and deck rail — subtract door openings for base, but keep the whole loop for crown." width="800" height="470" style="width:100%;height:auto;border:0" loading="lazy">
  </a>
  <figcaption style="font:14px/1.4 -apple-system,sans-serif;margin-top:6px;color:#555">
    Diagram: <a href="https://remodelcalculators.com/construction-diagrams/linear-feet-perimeter" target="_blank" rel="noopener">Perimeter = 2 × (length + width) — and why baseboard and crown deduct differently</a> — courtesy of <a href="https://remodelcalculators.com" target="_blank" rel="noopener">RemodelCalculators.com</a>
  </figcaption>
</figure>

Please keep the credit link intact and don't alter the diagram itself. Redistribution as part of a competing diagram library or template pack isn't permitted. Questions? Reach us via the site.

Was this diagram helpful?