Concrete Calculators
Every concrete calculator on Concrete Yard Planner in one place. Pick the tool that matches your project and get instant cubic yard, cubic feet, and bag estimates.
Free calculators • Instant estimates • DIY-friendly
Cubic Yards + Bags
Calculate in any unit you need—yards, feet, or bag counts.
5–10% Waste Option
Built-in spillage allowance to avoid shortages on site.
DIY-Friendly
Simple inputs, instant results—no construction math required.
Start Here
Not sure which calculator to use?
If your project is a flat pour like a patio or driveway, start with the main concrete calculator. It includes the live estimator, formulas, conversions, and worked examples in a single page.
Already know your project type? Jump straight to the right calculator below.
All Calculators
Three calculators are live today. More are on the roadmap—see what’s coming next below.
Slab Calculator
Estimate concrete for driveways, patios, garage floors, and other flat horizontal surfaces.
- Rectangular & custom shapes
- 4″ to 8″ thickness options
- Waste factor included
Bag Calculator
Convert cubic yards to number of bags and compare 40 lb, 60 lb, and 80 lb bag sizes for your project.
- 40, 60 & 80 lb bag sizes
- Instant bag count
- Cost comparison
Footing Calculator
Estimate concrete for isolated footings, deck supports, column bases, and pergola pads.
- Isolated footings
- Deck posts & column bases
- Cubic yards + bag counts
Post Hole Calculator
Calculate concrete volume for fence posts, deck posts, and anchoring applications.
- Fence posts
- Deck supports
- Multiple post layouts
Coming Soon
Column & Sonotube
Get estimates for cylindrical pours including sonotube forms and support columns.
- Cylindrical columns
- Sonotube forms
- Support pillars
Coming Soon
Stairs Calculator
Compute concrete requirements for outdoor steps, stair treads, and landings.
- Outdoor stairs
- Treads & risers
- Landing platforms
Coming Soon
Prefer Ready-Made Project Pages?
If you would rather skip the calculator and look up a common slab size, bag conversion, or footing dimension, browse our project pages.
Popular Guides
Learn concrete basics and best practices before you start calculating.
How Many Bags of Concrete Do I Need?
Learn how to calculate bag quantities, choose the right size (40, 60, or 80 lb), and avoid over-ordering for small pours.
Concrete Cost Per Yard
Understand pricing factors, compare ready-mix versus bagged concrete, and budget your project accurately.
Concrete Slab Thickness: 4″ vs 6″
Discover which thickness suits your project type, from light-duty patios to heavy driveways and garage floors.
How to Measure a Concrete Slab
Learn to measure rectangular, circular, and irregular shapes accurately to order the correct amount.
Picking the Right Calculator
Quick answers to help you choose the calculator that fits your project.
Which concrete calculator should I use?
Use the Slab Calculator for any flat pour like patios, driveways, sidewalks, garage floors, and shed pads. Use the Footing Calculator for isolated supports such as deck posts, pergola columns, and pier footings. Use the Bag Calculator when you already know your volume and just want to convert it into 40, 60, or 80 lb bags.
Do I need a separate calculator for round columns or post holes?
Round columns and post holes use a different formula (cylinder volume), so a dedicated tool gives more accurate results than the slab or footing calculator. We have a Sonotube/Column calculator and a Post Hole calculator on the roadmap. Until they ship, you can multiply π × radius² × height in feet to get cubic feet, then divide by 27 for cubic yards.
Can I calculate stairs or ramps with the slab calculator?
For ramps and lightly sloped slabs, use the slab calculator with the average thickness across the slope. For traditional stairs with treads and risers, the volume math is more complex and we recommend waiting for the dedicated stairs calculator on our roadmap, or breaking the structure down into rectangular blocks and adding the volumes manually.
What’s the difference between project pages and calculators?
Calculators let you input custom dimensions and get an estimate. Project pages are pre-built for common sizes (like a 12×18 slab at 6 inches, or a 24″ × 24″ × 36″ footing) so you can look up a result instantly. Use project pages for fast lookups, calculators when you need a custom answer.
Are these calculators free?
Yes. Every calculator on Concrete Yard Planner is free, requires no signup, and works on phone, tablet, and desktop.
What calculators are coming next?
Three new tools are on the roadmap: a Post Hole Calculator for fence and deck posts, a Column / Sonotube Calculator for cylindrical pours, and a Stairs Calculator for outdoor steps with treads and risers. Cards above mark them as “Coming Soon.”
About Our Calculators
Our concrete calculators are built for homeowners, DIY builders, and small contractors who need fast, reliable material estimates without unnecessary complexity. Every tool includes adjustable waste factors, multiple unit outputs (cubic yards, cubic feet, and bag counts), and clear plain-language guidance.
We focus on the most common residential concrete scenarios: slabs for patios, driveways and garage floors, footings for decks, pergolas and column supports, and bag quantity conversions for smaller pours. Calculators for post holes, cylindrical columns, and outdoor stairs are on the roadmap. Looking for the formulas and conversions behind the math? Visit our main concrete calculator page.
Disclaimer: Calculators provide estimates for planning purposes only. Actual concrete requirements vary based on site conditions, formwork accuracy, and material specifications. Always verify measurements, add appropriate waste factors, and consult product specifications. For structural or critical applications, consult a licensed engineer or contractor. We assume no liability for project outcomes.