Bag quantity planner
Turn your measurements into a concrete bag count.
Calculate the project volume, then compare common bag sizes using editable planning yields.
What are you pouring?
More shapes
For patios, driveways, walkways, shed pads, and other rectangular pours.
Diagram not to scaleEnter your measurements
Add a waste allowance
The suggested allowance reflects the selected project shape.
Compare purchase options
Supplier minimums and short-load fees vary. Confirm the full delivered price.
Add local price to estimate cost
How this estimate is calculated
This is a planning estimate. Confirm mix yield, sub-base, reinforcement, site conditions, structural requirements, and local code before ordering.
A reliable estimate in four steps
Measure once. See the math. Buy with confidence.
- 1Choose the project shape
Select the geometry that matches the concrete you are pouring.
- 2Enter measured dimensions
Use US or metric units and adjust individual fields when needed.
- 3Review the waste allowance
Use the project suggestion or enter a value that matches site conditions.
- 4Compare purchase options
Use the recommended bag count or ready-mix quote quantity as a starting point.
Project calculators
Start with a focused concrete estimate.
Enter the slab length, width, and thickness to estimate the order quantity, including your waste allowance.
Concrete Cost CalculatorGet the purchase amount from real measurements before comparing ready-mix and bagged concrete costs.
Concrete Footing CalculatorMeasure the total run, footing width, and depth to plan the concrete quantity before ordering.
Post Hole Concrete CalculatorEnter the hole diameter, depth, and count—not the post dimensions—to estimate bags or ready-mix volume.
Concrete Volume CalculatorEnter your dimensions and get instant volume estimates in multiple units, plus bag counts and ready-mix yardage.
How Much Concrete Do I Need? Calculator & GuideEnter your measurements to get an instant estimate of bags, cubic yards, and cost. Works for slabs, footings, post holes, stairs, columns, and tubes.
Concrete Mix CalculatorEnter your project dimensions to get volume estimates, then compare ready-mix delivery with bagged concrete using your local prices.
Concrete Driveway CalculatorEnter the length, width, and thickness of your driveway or patio to estimate the concrete order quantity, including waste allowance.
Concrete Column CalculatorEnter the column diameter and height to estimate the concrete volume, bag quantities, and cost.
Concrete Stairs CalculatorEnter the width, run, rise, and number of steps to estimate the concrete volume for your stair project.
Planning guidance
Common concrete estimate questions.
How much concrete does an 80 lb bag make?
This calculator uses 0.6 cubic foot as a planning yield for an 80 lb bag. Always confirm the yield printed on the product you plan to buy.
How many bags of concrete do I need for a 10x10 slab?
A 10×10 slab at 4 inches thick is about 3.5 cubic feet. With an 80 lb bag yielding roughly 0.6 cubic feet, you would need about 6 bags. Add 1–2 extra bags for waste and spillage.
How much extra concrete should I order?
A 5–10% allowance is common for regular forms. Uneven excavation, stairs, or uncertain measurements may justify 10–15%. The calculator suggests a starting point that you can change.
Should I use bags or ready-mix concrete?
Bagged concrete is often practical below 0.5 cubic yard. Between 0.5 and 1 cubic yard, compare mixing labor with local short-load fees. Above 1 cubic yard, start with a ready-mix quote.