Project-Based Calculators

Concrete Calculator for Every Project Type

Start from what you're actually building instead of a shape. Pick your project below for typical dimensions, or enter your own — then get cubic yards, cubic feet, cubic meters and bag counts instantly.

Quick reference: a 2-car driveway (20 × 24 ft, 4 in thick) needs about 6.5 cubic yards with waste. A 12×12 patio needs about 1.95 cubic yards. A 2-car garage slab needs about 5.4 cubic yards. Select your own project below for an exact number.

The Tool

Project Concrete Calculator

Choose a project preset to auto-fill typical dimensions, then adjust to match your actual site.

Presets use commonly cited average dimensions — always confirm against your actual site measurements before ordering.

Rectangular project slab diagram showing length, width and thickness L = 20 ft W = 24 ft T = 4 in
6.51Cubic Yards
175.8Cubic Feet
4.98Cubic Meters
58640lb Bags
39160lb Bags
29380lb Bags

For a truck-delivered volume this large, most suppliers recommend ready-mix over bagged concrete. See the bag calculator for brand-specific yields.

Methodology

How to Use the Project Calculator

  1. Pick your project

    Choose from 14 common presets, or select "Custom" to enter your own dimensions from scratch.

  2. Check the dimensions

    Presets use typical averages — measure your actual site and adjust length, width and thickness to match.

  3. Set your waste factor

    5% for simple, flat rectangular pours; 10% for anything irregular, sloped, or hand-mixed.

  4. Calculate

    Get cubic yards, cubic feet, cubic meters and bag counts instantly — no page reload.

Full Directory

Browse All Project Calculators

Every project type below links to its own dedicated calculator with project-specific guidance on thickness, reinforcement, and finish.

Driveway

Driveway

Standard 4–6 inch driveway slabs, sized to your vehicle count.

Patio

Patio

Outdoor living slabs from small pads to full backyard patios.

Walkway

Sidewalk / Walkway

Narrow, linear paths — calculated per linear foot of run.

Garage

Garage Slab

1, 2 and 3-car garage footprints with standard thickness presets.

Shed

Shed Foundation

Slab-on-grade foundations for storage sheds and workshops.

Foundation

House Foundation

Full foundation volume estimates for new-build planning.

Basement

Basement Floor

Below-grade slab pours, typically 4 inches over a vapor barrier.

Pool

Pool Deck

Surrounding decks sized to your pool's perimeter and walkway width.

Fence

Fence Posts

Bag counts per post, scaled to your total fence line.

Deck

Deck Footings

Pier and footing volumes for elevated deck framing.

Wall

Retaining Wall

Poured concrete retaining walls by length, height and thickness.

Steps

Steps / Porch

Stepped concrete for entryways and porch landings.

Curb

Curb & Gutter

Residential curb sections along driveways and lot lines.

Countertop

Concrete Countertop

Thin-pour volumes for kitchen and outdoor countertops.

Planter

Concrete Planter

Small DIY mold pours for garden planters.

Ornament

Birdbath / Ornament

Small decorative pours for garden features.

Sport Court

Sport / Basketball Court

Full-thickness slabs sized for backyard courts.

Carport

Carport Slab

Open-sided vehicle cover slabs, sized like a single driveway bay.

RV Pad

RV Pad

Long, reinforced pads sized to typical RV and trailer lengths.

Spa

Hot Tub / Spa Pad

Reinforced pads rated for concentrated static load.

Mailbox

Mailbox Post

Small single-post footings, similar sizing to a fence post.

Flagpole

Flagpole Base

Deep, narrow footings for wind-load stability.

Bench

Concrete Bench

DIY mold pours for garden and patio seating.

Barn

Barn / Pole Building Slab

Large agricultural and outbuilding floor slabs.

Workshop

Workshop Slab

Heavier-duty floors for tools, machinery and vehicle storage.

Stairs

Exterior Concrete Stairs

Outdoor stepped concrete, calculated per riser and tread.

Ramp

Concrete Ramp

Sloped slabs for accessibility and vehicle ramps.

Commercial

Parking Lot

Large-scale commercial paving volume estimates.

Utility

Sump Pit / Utility Pad

Small equipment pads for HVAC, generators and utility boxes.

Water Feature

Concrete Pond

Shell and basin volumes for water features and ponds.

Direct Answers

Frequently Asked Questions

How much concrete do I need for a 2-car driveway?

A typical 2-car driveway, roughly 20 ft × 24 ft at 4 inches thick, needs about 5.9 cubic yards before waste, or about 6.5 cubic yards with a 10% allowance.

How much concrete do I need for a 12x12 patio?

A 12 ft × 12 ft patio poured 4 inches thick needs about 1.78 cubic yards, or roughly 1.95 cubic yards with a 10% waste allowance.

How much concrete does a 2-car garage slab need?

A 20 ft × 20 ft, 2-car garage slab at 4 inches thick needs about 4.9 cubic yards before waste, or roughly 5.4 cubic yards with waste. Many garages use 5 inches instead, raising this to about 6.2 cubic yards.

Do I need rebar or wire mesh for a driveway?

Yes, for most residential driveways. Wire mesh or rebar on a grid helps control cracking under vehicle load. Fiber-reinforced concrete is sometimes used as a lighter-duty alternative. See the rebar calculator for spacing guidance.

What thickness should a shed foundation be?

Most shed slabs are poured 4 inches thick, matching standard residential slab practice. Sheds storing heavy equipment or vehicles may warrant 5–6 inches with reinforcement.

Related Calculators

Explore by Shape or Material Instead

Every project above is built from an underlying shape. If your pour doesn't match a preset, start from the shape itself.