How to calculate internal plaster quantity with IS code deduction?

Measure wall area, subtract door/window areas, if any opening exceeds 30 sq.ft, add jamb (2 sides) and soffit area back. Our calculator automates this.

What is jamb and soffit in plastering?

Jambs are vertical sides of opening, soffit is top horizontal face. As per IS 1200, for openings >30 sq.ft, these are plastered and added to quantity.

Where can I download plaster calculation excel sheet?

Click the Download Excel Sheet button above or join WhatsApp channel to get free ready-to-use plaster BOQ excel file.

12 mm Internal Plaster Calculator | IS Code Deduction + BOQ with GST | Free Excel Download

🧱 12mm Internal Cement Plaster Calculator + IS Code Deductions & BOQ with GST

Professional tool for internal plaster quantity calculation as per IS 1200 (Part 5) norms. Automatically deducts doors/windows, adds jamb & soffit plaster for openings > 30 sq.ft, and generates detailed Abstract Sheet with 18% GST.

📥 Download Internal Plaster Excel Sheet

Ready-to-use BOQ format & Measurement Sheet — Join WhatsApp to access

📊 Download Excel Sheet 💬 Join WhatsApp Channel

Ground floor working drawing for internal plaster measurement - 12mm internal cement plaster layout

📐 Ground Floor Working Drawing – Reference for internal wall plaster measurement & room dimensions

📐 12mm Internal Plaster Material Calculation + IS Code Deductions

✅ IS 1200 compliant Deduct openings & auto-add jambs/soffits when opening area > 2.787 m² (30 sq.ft)

📏 Wall Length (m)

📐 Wall Height (m)

🎨 Plaster Thickness

🧱 Cement:Sand Ratio

🚪 Door & Window Deductions (as per IS Code)

Door Width (m)

Door Height (m)

No. of Doors

Window Width (m)

Window Height (m)

No. of Windows

Jamb/Soffit Depth (m) (standard 0.075m)

Opening > 30 sq.ft (2.787 m²)➡️ Jambs + Soffit added automatically

Result will appear here — Enter wall dimensions, doors, windows and click calculate.

📋 Internal Plaster Measurement Sheet (Sample Project)

Actual site measurement for 12mm plaster (1:6) including deductions & additions as per IS code. Free Excel sheet available via WhatsApp channel.

Item No	Description	No	Length (ft)	Breadth/Height (ft)	Quantity (sq.ft)

Total Net Plaster Area (after deduction + jamb/soffit): 3028.43 sq.ft = 281.45 m²

📑 Abstract Sheet / BOQ (Bill of Quantities) with 18% GST

Rate analysis for 12 mm internal cement plaster (1:6) including material, labour, and overheads. Final amount inclusive of GST.

Description	Unit	Quantity (m²)	Rate (₹/m²)	Amount (₹)
12 mm thick internal cement plaster (1:6) incl. scaffolding, curing	m²	281.45	285	80213.25
Subtotal (Excluding GST)				80213.25
GST @ 18%			18%	14438.39
💰 Total Amount (Including 18% GST)				94651.64

📊 Rate Analysis (per m²) for 12mm Internal Plaster 1:6

Component	Quantity	Rate (₹)	Cost (₹/m²)
Cement (bags)	0.092 bags	380/bag	34.96
Sand (m³)	0.014 m³	1600/m³	22.40
Labour (Mason + Helper)	0.20 days	1200	175.00
Water, scaffolding, tools	LS	-	22.64
Base Rate per m²			255.00 + contingencies = ₹285/m²

📐 IS Code Deduction Norms (IS 1200 Part 5) Applied in Calculator:
✅ For each opening (door/window): If area > 2.787 m² (30 sq.ft) → Jamb area = 2 × (Height × Depth) per opening + Soffit area = Width × Depth is ADDED BACK after full deduction.
✅ For openings ≤ 30 sq.ft: No jamb/soffit addition (standard deduction only).
✅ Calculator automatically computes net plaster area and material.