Free Concrete Calculators
for Every Project

ACI & ASTM-based formulas for precise concrete volume, mix, cost, and reinforcement calculations — trusted by contractors, structural engineers, and DIY builders for slabs, footings, steps, driveways, walls, and more.

Reports with 3d visuals
10 Tool Categories
ACI & ASTM Standard
100% Free

Concrete calculator by Features

Browse concrete calculators by project type, including slab concrete calculator, concrete patio calculators, concrete driveway calculators, concrete foundation calculators, concrete footing calculator, concrete yardage calculator, concrete mix calculator, rebar calculators, and concrete estimating tools.

Slab Concrete Calculator Concrete Patio Calculators Concrete Driveway Calculators Concrete Foundation Calculators Concrete Footing Calculator Concrete Floor Calculators Concrete Wall Calculator Sontube Calculators Concrete Block Calculators Rebar Calculators Sand Calculators Concrete Mix Calculator Epoxy Calculators Concrete Resurfacing Calculators Concrete Calculators Yardage Concrete Sidewalk Calculators
Concrete Calculator SEO Sections — Concrete Depot
Quick start

How to use our concrete calculators

Use any Concrete Depot calculator to estimate concrete yards, cubic feet, bags, material cost, formula steps, and a clean project report.

01

Enter your project measurements

Add the length, width, thickness, depth, diameter, height, or other measurements needed for your concrete project.

02

Choose units, waste, and bag size

Select the right unit system, add a waste allowance, and choose the bag size or ready mix setting used for your estimate.

03

Review yards, bags, cost, formula, and report

Check the concrete volume, bag count, cost estimate, formula used, calculation steps, and printable report before ordering.

For best results, measure in the same unit system and check final quantity with your supplier or contractor.
Built for real jobs

Concrete Calculators for DIY, Contractors, and Estimators

Our concrete estimating tools help homeowners, crews, and students plan concrete volume, bags, cost, and material checks with simple project inputs.

DIY homeowners

Use a DIY concrete calculator for patios, slabs, walkways, post holes, pads, shed bases, and small repair projects.

DIY concrete calculator bag estimate

Contractors

Use a contractor concrete calculator to check cubic yards, waste, ready mix quantity, bags, job cost, and project reports.

contractor concrete calculator construction concrete calculator

Students and estimators

Use a concrete estimator calculator to learn formulas, compare shape types, follow steps, and prepare quantity takeoffs.

concrete estimator calculator concrete estimating tools
Formula guide

Common Concrete Calculator Formulas

These common concrete formulas show how slab, wall, footing, post hole, round slab, and step calculators estimate concrete volume.

Slab concrete formula

Used for slabs, patios, driveways, pads, and sidewalks.

Volume = Length × Width × Thickness

Wall concrete formula

Used for concrete walls, retaining walls, and vertical pours.

Volume = Length × Height × Thickness

Footing concrete formula

Used for strip footings, grade beams, curbs, and support bases.

Volume = Length × Width × Depth

Post hole concrete formula

Used for fence posts, deck piers, tubes, and Sonotube-style forms.

Volume = π × Radius² × Depth × Quantity

Round slab concrete formula

Used for circular patios, round pads, and round concrete bases.

Volume = π × Radius² × Thickness

Concrete steps formula

Used for stair pours with width, rise, run, and number of steps.

Volume = Step area × Width × Number of steps
Help center

Concrete calculators FAQ

Clear answers for common concrete estimating questions, from concrete yards and bag counts to waste, slab thickness, and saved reports.

How do I calculate concrete yards?
Multiply length × width × thickness to get cubic feet. Then divide cubic feet by 27 to get cubic yards. Make sure all measurements are converted to feet before using the concrete yard formula.
How many bags of concrete do I need?
Find the total concrete volume in cubic feet, then divide it by the bag yield. A 60 lb bag is often estimated at about 0.45 cu ft, and an 80 lb bag at about 0.60 cu ft. Always round up to the next full bag.
How much extra concrete should I order?
Many projects use a waste allowance of 5% to 10%. Use more for uneven subgrade, complex shapes, thickened edges, or projects where small shortages would delay the pour.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in one cubic yard. That is why most concrete calculators divide cubic feet by 27 to show concrete yards.
What thickness should I use for a concrete slab?
A 4 inch slab is common for many patios, walkways, and light-use pads. Driveways and heavier use areas often need 5 to 6 inches or more. Always check local code, soil conditions, reinforcement needs, and contractor guidance.
Is ready mix cheaper than concrete bags?
For larger pours, ready mix is often easier and may cost less per cubic yard. Concrete bags can make sense for small jobs, repairs, post holes, or projects where delivery fees are too high.
Can I use the same calculator for slabs, patios, and driveways?
Yes, a slab concrete calculator can estimate many flat rectangular projects when the shape is the same. For better detail, use a dedicated patio concrete calculator, driveway calculator, footing calculator, or round slab calculator when the project needs special inputs.
Do concrete calculators include waste?
Most Concrete Depot calculators include a waste field. This lets you compare base volume with order quantity, so you can plan extra concrete for spillage, uneven ground, and small measurement changes.
Can I download or print my concrete estimate?
Yes. Dashboard-ready Concrete Depot tools can include a printable report with inputs, results, formulas, calculation steps, and a 3D measurement diagram.
Can I save my concrete report?
Yes. When report saving is active, you can save a concrete report to your Concrete Depot dashboard and return to it later for review, printing, or project tracking.