About FreeConcreteCalc

What We Do

FreeConcreteCalc is a free online concrete calculator designed for homeowners, DIY enthusiasts, and professional contractors. We help you figure out exactly how much concrete you need — in bags, cubic yards, or cubic feet — before you head to the hardware store or call a ready-mix supplier.

Our tool covers 8 project types: slabs, footings, round post holes, square post holes, walls, columns, stairs, and curbs. It includes features like adjustable waste factor, cost estimation, rebar calculation, multi-zone project building, and shareable calculation URLs — all completely free with no account required.

Why We Built This

We got tired of concrete calculators that were either too basic (only slabs), biased toward one brand (Quikrete and Sakrete calculators only recommend their own products), or buried under intrusive ads that made them unusable on mobile.

We wanted a tool that:

• Handles any concrete project shape — not just rectangles
• Shows bag counts for multiple sizes simultaneously
• Includes a waste factor so you never run short mid-pour
• Works on any brand of concrete — Quikrete, Sakrete, or store brands
• Tells you when ready-mix truck delivery makes more sense than bags
• Works perfectly on a phone at the jobsite
• Loads instantly without heavy ads blocking the results

So we built it.

How It Works

FreeConcreteCalc runs entirely in your browser. Your calculations are performed on your device — nothing is sent to a server. This means:

• Instant results with no loading time
• Your project data stays private
• Works offline once the page loads
• No account, no email, no signup required

The formulas we use are based on standard geometric volume calculations with bag yields sourced from manufacturer specifications (0.6 cu ft per 80lb bag, 0.45 cu ft per 60lb bag). All pricing references are approximate national averages updated regularly.

Our Commitment to Accuracy

We take accuracy seriously. Our calculator formulas are verified against published engineering references and manufacturer data. However, concrete calculations are inherently estimates — real-world factors like uneven ground, form imperfections, and mixing inconsistencies mean actual material usage may vary by 5–15% from calculated values.

That's why we include an adjustable waste factor (defaulting to 10%) and always recommend rounding up when ordering materials. Running short mid-pour is far more expensive than having a few extra bags.

Brand Neutral

Unlike calculators from Quikrete or Sakrete that only recommend their own products, FreeConcreteCalc is completely brand-neutral. We show bag counts that work for any manufacturer's concrete because standard bag yields are the same across brands for equivalent weights. We also recommend ready-mix truck delivery when it makes economic sense — something brand calculators never do because they sell bags.

Features at a Glance

Get Started

Ready to calculate? Head to our concrete calculator and enter your first project dimensions. No signup, no download — just instant results.

Have questions or feedback? Visit our contact page.