ganak.appConcrete Calculator
Estimate concrete volume in yards, feet, or meters for slabs, footings, walls, and columns. Includes bag count and cost estimates.
Flat rectangular slab: length × width × thickness.
Bag count, cost, and weight. Override yield if needed.
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Order & cost summary
Volume, bags, weight & cost at a glance
What is a Concrete Calculator?
Overview of the tool and what it helps you estimate.
A concrete calculator (also called a concrete volume or yardage calculator) estimates how much concrete you need for slabs, pads, footings, walls, columns, stairs, and curbs. It converts volume into cubic yards, cubic feet, and cubic meters, so you can order ready-mix or plan bag counts with confidence. If you're searching for a concrete slab calculator, concrete footing calculator, or concrete yard calculator, this tool covers all of them in one place.
Use it to answer: how much concrete do I need? Add your dimensions, choose a shape, and the calculator handles conversions, waste, and optional cost estimates.
Concrete Volume Formulas
Core formulas used for slabs, columns, stairs, and more.
The calculator uses standard volume formulas and then applies unit conversions. These are the same formulas contractors use when they calculate concrete by hand.
Rectangular slab, wall, or footing
Round column / tube
Stairs (solid)
Conversions: 1 cubic yard = 27 cubic feet. 1 cubic meter = 35.3147 cubic feet. This is how to calculate yards of concrete from a measured volume.
Bags, Ready-Mix, and Cost Estimates
Compare bagged vs ready-mix and estimate costs.
For small pours, bags are convenient. For larger pours, ready-mix is usually cheaper and faster. This calculator estimates bag count using the yield per bag and compares cost if you enter prices.
- Bag count = Total volume ÷ yield per bag (rounded up).
- Ready-mix cost = Volume (yd^3 or m^3) x price per yard/m^3.
- Bagged cost = Bag count × price per bag.
If you're searching for a concrete cost calculator or concrete bag calculator, the pricing panel handles both.
Concrete Calculator Examples
Sample pours with volume and waste included.
Example 1: Slab
- 10 ft × 10 ft × 4 in
- Volume ~ 1.23 yd³
- With 10% waste ~ 1.36 yd³
Example 2: Footing
- 20 ft × 2 ft × 1 ft
- Volume ~ 1.48 yd³
- With 10% waste ~ 1.63 yd³
Example 3: Round Column
- 12 in diameter × 8 ft
- Volume ~ 0.23 yd³
- With 10% waste ~ 0.26 yd³
Example 4: Wall
- 12 ft × 8 ft × 6 in
- Volume ~ 1.78 yd³
- With 10% waste ~ 1.96 yd³
Assumptions and Waste Factor
Why waste is included and how rounding works.
Concrete orders usually include extra to cover spillage, uneven forms, and finishing losses. Ganak defaults to a 10% waste factor, and the suggested order rounds to common delivery increments (0.25 yd^3 or 0.1 m^3).
If you're placing a ready-mix order, rounding up avoids short pours and costly partial loads.
Common Mistakes to Avoid
Quick checklist to prevent short pours.
- Forgetting slab thickness or mixing feet with inches or meters with centimeters.
- Using interior dimensions instead of form dimensions.
- Skipping waste allowance for uneven subgrades or form loss.
- Not multiplying by quantity for repeat pours (posts, steps, columns).
Pro Tips for Accurate Orders
Small habits that improve accuracy and reduce waste.
- Measure twice and keep units consistent throughout.
- Use the bag yield printed on the mix for best accuracy.
- Order ready-mix for large pours; bags for small patch jobs.
- When in doubt, round up your order to the next delivery increment.
Frequently Asked Questions
Common questions and detailed answers