Concrete Calculator Hub: Choose a Tool
Use the calculators below to plan concrete and masonry projects with confidence. Get quick material estimates in metric or imperial, convert between cubic feet, cubic yards, and cubic meters, and reduce the risk of running short by accounting for typical waste, over-excavation, and real-world conditions.
Common searches this page supports:
concrete calculator • how much concrete do I need • concrete volume calculator • concrete yardage calculator • slab calculator • footing calculator
Concrete Slab Calculator
Estimate cubic yards/meters for patios, driveways, and floors. Includes thickness guidance and bag vs truck planning.
Open slab calculator →Concrete Footing Calculator
Calculate foundation and strip footing concrete volume for pads and post holes using your exact dimensions.
Open footing calculator →Concrete Bag Calculator
Convert volume into 40/60/80 lb bag counts (or your local bag sizes) for small pours and DIY projects.
Open bag calculator →Rebar Calculator
Estimate bar count, spacing, total length, and steel weight for slabs and footings to support reinforcement planning.
Open rebar calculator →Brick Calculator
Calculate brick quantities and basic mortar planning for walls, facades, and common masonry projects.
Open brick calculator →What These Concrete Tools Help You Calculate
- Concrete volume: cubic yards, cubic feet, or cubic meters for slabs, footings, and pads.
- Concrete bags: approximate bag counts for DIY pours and small projects.
- Ready-mix ordering: yardage totals that help you order from a concrete supplier.
- Reinforcement planning: rebar quantities, spacing layouts, and estimated steel weight.
- Masonry quantities: brick counts for walls and common builds.
How to Calculate Concrete Volume
The simplest way to calculate how much concrete you need is to multiply the project’s length × width × depth. This gives you a volume in cubic units (cubic feet or cubic meters). From there, convert to the ordering unit used in your region — typically cubic yards (US ready-mix) or cubic meters (metric regions).
Concrete Volume Formula
Volume = Length × Width × Depth
Example: 20 ft × 20 ft slab at 4 inches thick
- Convert thickness: 4 inches ÷ 12 = 0.33 ft
- Volume in cubic feet: 20 × 20 × 0.33 = 132 ft³
- Convert to cubic yards: 132 ÷ 27 ≈ 4.9 yd³
- Recommended ordering: add 5–10% → ~5.2–5.4 yd³
Quick Conversions
| Conversion | Result |
|---|---|
| 1 cubic yard (yd³) = | 27 cubic feet (ft³) |
| Cubic feet → cubic yards | Divide by 27 |
| Inches → feet | Divide by 12 |
| Millimeters → meters | Divide by 1000 |
Want the fastest answer? Use the Concrete Slab Calculator for flat pours or the Concrete Footing Calculator for foundations and trenches.
Concrete Slab Calculator Guide
Slabs are one of the most common pours (patios, shed bases, floors, and driveways). The two biggest drivers of volume are the footprint and the thickness.
- Common slab thickness: 4" (light-duty), 5–6" (driveways / heavier loads), and thicker for special applications.
- Base preparation matters: uneven sub-base can increase the concrete needed.
- Reinforcement: use mesh or rebar when appropriate and follow local guidance.
Calculate your slab quickly with the Concrete Slab Calculator.
Concrete Footing Calculator Guide
Footings support loads and transfer weight to the ground. They’re commonly used for walls, decks, fences, and foundations. Because footing sizes can vary by soil conditions and loads, confirm the required dimensions before ordering.
- Common footing types: strip footings, pad footings, and pier/post holes.
- Depth varies: local code, frost depth, and soil conditions can impact required depth.
- Over-excavation: trenches often end up wider than planned — factor this into your estimate.
Estimate your footing volume using the Concrete Footing Calculator.
Ready-Mix vs Bagged Concrete
Bagged concrete is convenient for small projects, while ready-mix is typically more efficient for larger pours and provides more consistent mix quality. The best option depends on your project size, access, and time constraints.
- DIY and small pours: bagged concrete is often ideal for posts, small pads, repairs, and steps.
- Larger slabs and foundations: ready-mix is commonly recommended to reduce labor and improve consistency.
- Rule of thumb: 1 cubic yard is roughly equivalent to 45–50 80 lb bags (varies by yield and mix).
If you’re using bags, the Concrete Bag Calculator will convert your volume estimate into bag counts.
Common Concrete Estimating Mistakes (and How to Avoid Them)
- Forgetting waste: add 5–10% to cover spillage and uneven base conditions.
- Using the wrong thickness: confirm the required depth before you calculate.
- Not converting units correctly: inches → feet, cubic feet → cubic yards, or mm → meters.
- Ignoring site logistics: access, wheelbarrow distance, and pour time can affect how you order and place concrete.
- Overlooking reinforcement planning: use the Rebar Calculator for basic planning and budgeting.
Quick Tips for Better Concrete Estimates
- Measure twice and round up slightly to cover waste, spillage, and uneven sub-base.
- For larger pours, consider the logistics: access, wheelbarrow distance, or pump truck requirements.
- Use reinforcement where needed (mesh or rebar) and follow local building guidelines.
- Footings and slabs can vary by load and soil conditions — confirm specs before ordering.
For formulas, assumptions, and calculation standards, see our Methodology and Data Sources.
Content reviewed for material estimation accuracy using standard geometric volume formulas and industry conversion references.
Frequently Asked Questions About Concrete Calculations
How many cubic feet are in a cubic yard?
One cubic yard equals 27 cubic feet.
How much concrete do I need for a 10×10 slab?
A 10×10 slab at 4 inches thick requires about 1.2 cubic yards. Add 5–10% extra to cover waste and uneven sub-base conditions.
How do I convert cubic feet to cubic yards?
Divide the total cubic feet by 27.
Should I order extra concrete?
Yes. It’s common to add 5–10% extra to cover spillage, uneven excavation, and minor measurement errors.
When should I use ready-mix instead of bags?
Bags are practical for small DIY pours. For larger slabs, foundations, or multiple pours, ready-mix is typically faster and more consistent.
Important Estimate Disclaimer
The results provided by these calculators are general estimates only and should not be considered precise engineering measurements. Actual material requirements can vary based on site conditions, local building codes, soil, reinforcement needs, climate exposure, and intended use.
These tools help you plan and budget, but they do not replace professional advice from a qualified contractor, engineer, or building inspector. Always verify dimensions and project specifications before ordering materials.
For more information on assumptions and formulas, see our Data Sources and Methodology.