Cement Calculator for RCC Slabs — Bags, Sand & Crush
Under-ordering cement stops your slab pour halfway; over-ordering wastes money and hardens in the store. This cement calculator uses the standard dry-volume method (wet volume × 1.54, split by mix ratio) so you order the right number of bags for one continuous pour.
Quick Answer
A 100 cft (about 2.8 m³) M20 (1:1.5:3) RCC slab needs roughly 23 bags of 50-kg cement, 42 cft sand and 84 cft crush (aggregate). Enter your slab dimensions below to get exact bags and volume for M15, M20 or M25 concrete.
Cement Calculator (RCC Slab)
How to Use the Cement Calculator (RCC Slab)
- 1Measure the slab: length × width × thickness in feet (4″ or 5″ thickness is typical for homes).
- 2Pick your concrete mix — M20 (1:1.5:3) is the common choice for residential slabs in Pakistan.
- 3Enter the quantities to get cement bags, sand (cft), crush (cft) and water requirement.
- 4Add 3–5% margin for spillage and order all cement for a single-day pour.
Frequently Asked Questions
How many cement bags are needed per cft of concrete?
For M20 (1:1.5:3) concrete, plan roughly 0.23 bags (50 kg) per cft — about 23 bags per 100 cft. M15 (1:2:4) needs about 0.19 bags per cft and M25 about 0.27 bags per cft.
How many bags of cement for a 5 marla house slab?
A typical 5 marla (about 1,350 sq ft covered) 4″ slab with beams needs roughly 180–230 cement bags for the slab pour alone, plus more for beams, columns and lintels. Calculate your exact slab size above.
Which cement is best for RCC slab in Pakistan?
Use a reputable OPC 53 grade brand — Cherat, Fecto, Flying Pakistan, Bestway and Maple Leaf are all common for slabs. Consistency of brand across one pour matters more than the logo; never mix brands in the same slab.
What is the 1.54 dry volume factor?
Cement, sand and crush are ordered by dry volume, but slabs are poured wet. Wet concrete shrinks about 54% when ingredients are dry-measured, so calculators multiply wet volume by 1.54 to get the dry volume to split by mix ratio.
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