Studio Matrx Monthly · Volume 1 · Issue 1 · June 2026
Amogh N P
 In loving memory of Amogh N P — Architect · Designer · Visionary 
Door Frame Timber Calculator

Door Frame Timber Calculator

Enter the door size, the rebate and section, and your ₹/rft rate — and get the running feet of chowkhat section, timber volume in CFT, holdfast count and the all-in cost with 18% GST. A standard 900 × 2100 frame works out to about 17-18 rft. Indicative India 2026 — confirm on site.

Your frame

One rebate; common internal door. Door 900 × 2100 mm, section 3.00 × 4.00 in. Running feet = 2 jambs + head (no sill). Timber rate quoted per running foot of section; holdfasts 3 per jamb. Indicative India 2026 — varies by timber grade, city and carpenter.

Running feet of section (per frame)

0.0 rft

1.49 CFT timber · 6 holdfasts · 8,914/frame incl GST

Section

17.90 rft

Timber

1.49 CFT

volume

Holdfasts

6

3 / jamb

Per frame

₹8,914

incl GST

Frames

1

quantity

Total

₹8,914

incl GST

  • Material6,265
  • Fixing390
  • Labour900
  • GST1,360

Per-frame split: material vs fixing vs labour, plus 18% GST. Indicative — confirm with your carpenter.

Spec the right chowkhat for every opening

DesignAI matches timber species, section size and rebate to each door's use, your climate and termite risk — and sense-checks the quantity and rate.

How this is worked out

Running feet of section = 2 jambs (door height + a section-depth allowance for the head joint) + the head (door width + both jamb sections). A standard 900 × 2100 single-rebate frame comes to roughly 17-18 rft with no sill. Timber volume in CFT = running feet × the section cross-section area, scaled up for a double rebate or deeper section.

Holdfasts are taken at 3 per jamb (6 per frame), embedded in cement concrete — timber frames are fixed with holdfasts or screws-and-plugs; steel frames are grouted with 1:3 mortar instead. Always set the frame plumb, level and square — that is non-negotiable — and provide DPC / anti-termite treatment at the frame base, which matters in India. Costs include material (section × rate), fixing (holdfasts), labour and 18% GST.

Figures are indicative for India 2026 — confirm with your carpenter or fitter on site and measure twice. This is a guidance tool, not a substitute for a skilled carpenter or site engineer.