Concrete Calculator
Estimate cement, sand, and aggregate for slabs, columns, footings, and stairs.
Material cost estimate (optional)
How to calculate concrete
Three simple steps to a job-ready material list.
Slab, column, footing, or stairs — choose the shape closest to what you're pouring.
Add length, width, and depth in your preferred units. Mix metric and imperial freely.
Cement bags, sand, aggregate, and water — broken down with wastage already factored in.
Concrete Calculator — Free & Accurate
Our concrete calculator helps builders, contractors, and DIYers work out exactly how much cement, sand, and aggregate they need for any pour. Enter your slab, column, footing, or stair dimensions, pick a mix ratio, and get a complete material list in seconds.
The calculator uses the standard dry-volume conversion factor of 1.54 to account for the fact that wet concrete shrinks during mixing. Pick from common Indian and international mixes — M15, M20, M25, and M22.5 — or adjust wastage between 0% and 15% to match site conditions.
Results show volume in cubic metres, cubic feet, and cubic yards, plus a clean breakdown of cement bags (50 kg), sand, coarse aggregate, and water needed at a 0.5 water-cement ratio. Everything runs in your browser — no signup, no data sent to any server.
Why use this calculator?
Built for the site, not the spec sheet — simple, fast, and accurate.
No spreadsheets, no formulas to memorise. Type your sizes, hit calculate, and you're done.
Uses the 1.54 dry-volume factor and standard mix ratios. Same formulas a site engineer would use.
Everything runs in your browser. Your dimensions never leave your device.
Mix metres, feet, inches, and centimetres on the same job — the math converts cleanly.
Add 5%, 10%, or 15% wastage with one tap. Realistic numbers for real sites.
Open it on your phone right at the pour. Fully responsive, no app needed.
Related construction tools
Free, browser-based, and built the same way as the concrete calculator.
Frequently asked questions
For most residential slabs, footings, and pathways, M20 (1 : 1.5 : 3) is the standard mix. Use M25 for load-bearing columns and beams, and M15 for non-structural pours like floor leveling or lean concrete.
When you mix dry cement, sand, and aggregate with water, the material shrinks because water fills the voids between particles. The 1.54 factor accounts for this shrinkage, so the calculator gives you enough dry material to produce your target wet volume.
Cement is calculated at 1440 kg/m³ density and rounded up to the nearest 50 kg bag. The estimate is accurate within a few percent for typical site conditions — always round up when ordering to cover real-world losses.
Yes. Every dimension has its own unit picker, so you can enter length in feet, width in metres, and thickness in inches on the same calculation. The math converts everything to consistent units internally.
Completely. No signup, no watermarks, no daily limits. All math runs in your browser — your project dimensions are never uploaded anywhere.