Estimate How Many QUIKRETE® Concrete Mix Bags You May Need For A Slab, Pad, Post Hole Or Known Concrete Volume. Choose A Bag Size, Enter Your Dimensions, Add A Waste Allowance And Optional Bag Price, Then Compare The Result With The Exact Product Data Sheet Before Buying.
Independent estimating tool. ConcreteCreek.com is not affiliated with or endorsed by The QUIKRETE Companies. QUIKRETE® is a trademark of its respective owner.
Select A Project Type, Then Enter Your Measurements. All Numeric Fields Start With A Clean 0 Placeholder Only, So Typing 25 Produces 25 — Not 025.
Your Result Will Appear Here After You Press Calculate QUIKRETE Bags.
Bag quantities are rounded up to whole bags for purchase planning. Always compare the result with the exact package and current QUIKRETE product data sheet.
Concrete volume is calculated first. The required volume, including your waste allowance, is then divided by the selected bag yield and rounded up to a whole bag.
The calculator keeps volume, bag yield, bag count and cost separate so you can see exactly what drives the estimate.
See the geometric concrete quantity in cubic feet before it is converted into bags.
View the same result in cubic yards for easy comparison with ready-mix quantities.
The purchase estimate rounds up so a fractional bag does not leave the project short.
Add your own allowance for imperfect forms, excavation and site variation.
Enter your local price per bag for a simple material-only budget.
Save the calculation summary with the selected bag size and project measurements.
A bagged-concrete estimate starts with the volume of the space you intend to fill. For a rectangular slab or pad, multiply length by width by thickness after converting the thickness from inches to feet. For a cylindrical post hole, calculate the cylinder volume and, when appropriate, subtract the volume occupied by the post. Once the concrete volume is known, divide it by the approximate mixed yield of the exact bag size.
QUIKRETE’s current Concrete Mix product page lists 40, 50, 60 and 80 lb packages, while the current Concrete Mix data sheet also lists a 90 lb regional package. The data sheet gives approximate yields of 0.30 ft³ for 40 lb, 0.375 ft³ for 50 lb, 0.45 ft³ for 60 lb, 0.60 ft³ for 80 lb and 0.675 ft³ for 90 lb bags. Because these are approximate yields, the finished bag count should still be checked against the product data sheet and real site conditions.
Bags = Concrete Volume (ft³) ÷ Yield Per Bag (ft³), Rounded Up| Bag Size | Approx. Yield | Bags Per 1 ft³ | Approx. Bags Per 1 yd³ |
|---|---|---|---|
| 40 lb | 0.30 ft³ | 3.34 | 90 |
| 50 lb | 0.375 ft³ | 2.67 | 72 |
| 60 lb | 0.45 ft³ | 2.23 | 60 |
| 80 lb | 0.60 ft³ | 1.67 | 45 |
| 90 lb | 0.675 ft³ | 1.49 | 40 |
For a slab measured in feet and inches, convert thickness to feet by dividing inches by 12. A 4 inch slab is 0.3333 ft thick. Then multiply length × width × thickness. If there are several identical pads, multiply by the quantity before adding waste.
Volume (ft³) = Length (ft) × Width (ft) × [Thickness (in) ÷ 12]A round post hole is a cylinder. Convert the hole diameter and depth from inches to feet, divide the diameter by two to obtain the radius, and calculate π × radius² × depth. If you enter a post diameter, the calculator subtracts the post cylinder from the hole cylinder before multiplying by the number of holes.
Bag weight alone is not a volume measurement, but it is linked to the approximate yield stated for a specific product. A project requiring 12 cubic feet of mixed concrete needs about 20 bags if an 80 lb bag yields 0.60 ft³, but about 27 bags if a 60 lb bag yields 0.45 ft³. This is why a calculator should not use one generic “bags per project” number for every package size.
No single waste percentage fits every job. A carefully formed slab on a uniform base can often be measured more closely than hand-dug post holes or rough excavation. The calculator allows you to enter your own percentage instead of forcing a default. Recheck forms, hole dimensions and excavation immediately before buying material.
Bagged concrete is convenient for repairs, steps, small slabs, equipment pads, fence posts and other jobs where a ready-mix delivery may be impractical. As volume rises, however, the number of bags, mixing time, lifting and water-control effort can become substantial. Compare the bag estimate with a Concrete Delivery Calculator or Concrete By The Yard Calculator when the project becomes large.
For other planning workflows, use the Concrete Bag Coverage Calculator, Concrete Post Hole Calculator, Concrete Footer Calculator, or Concrete Volume Calculator. These tools help separate geometry from product selection so you can check the numbers from more than one direction.
This calculator does not select a concrete product or structural specification. QUIKRETE Concrete Mix No. 1101 is described by the manufacturer as a general-purpose pre-blended concrete mix, while other QUIKRETE products have different performance targets and applications. Use the product required for the job and follow the current technical data, local code and project documentation.
Do not add water based only on appearance or a generic online ratio. The current QUIKRETE Concrete Mix data sheet gives package-specific starting and maximum expected water contents, and warns that the correct consistency and placement procedures matter. Follow the current package and data sheet. Excess water can reduce concrete performance.
Dry cementitious materials can expose workers to dust and wet concrete can cause serious skin and eye injury. The QUIKRETE data sheet directs users to read the Safety Data Sheet and wear appropriate gloves, mask and eye protection. For occupational work, also follow applicable local safety requirements and exposure controls.
These examples use geometry and the approximate Concrete Mix yields above. Real purchase quantities should be checked against the exact product and site.
| Example | Concrete Volume | Bag Size | Approx. Yield | Whole Bags |
|---|---|---|---|---|
| Small Pad | 6.0 ft³ | 80 lb | 0.60 ft³ | 10 |
| Small Slab | 12.0 ft³ | 80 lb | 0.60 ft³ | 20 |
| Same 12 ft³ Volume | 12.0 ft³ | 60 lb | 0.45 ft³ | 27 |
| One Cubic Yard | 27.0 ft³ | 80 lb | 0.60 ft³ | 45 |
| One Cubic Yard | 27.0 ft³ | 60 lb | 0.45 ft³ | 60 |
Common questions about bag sizes, yields, slabs, post holes, waste and bagged-concrete estimating.
Using the approximate 0.60 ft³ yield listed in the current Concrete Mix data sheet, 27 ft³ ÷ 0.60 ft³ = 45 bags.
At an approximate 0.45 ft³ yield per 60 lb bag, one cubic yard requires 27 ÷ 0.45 = 60 bags.
Yes. Material purchases are shown as whole bags rounded upward, consistent with the practical approach used by QUIKRETE’s own calculator.
Yes. Enter the slab length and width in feet and enter 4 inches for thickness. The calculator converts the thickness to feet before calculating volume.
Yes. Enter hole diameter, depth, optional post diameter and the number of holes. The calculator estimates the cylindrical concrete volume.
Different packaged concrete products can have different yields. Custom yield lets you use the current data sheet for the exact product rather than assuming Concrete Mix No. 1101 values apply to every product.
No. The price field is a simple price-per-bag multiplier. Add taxes, delivery, pallet charges, tool hire and other costs separately if they apply.
No. This is an independent calculator from ConcreteCreek.com. For official product calculations and current product information, use QUIKRETE’s own calculator and technical data.
Use the custom yield from the current QUIKRETE 5000 data sheet unless you have verified that the selected yield matches the package you are buying. Product formulations, sizes and availability can differ.
Uneven substrate, over-excavation, larger holes, spills, incomplete bag yield, measurement error and waste can increase actual consumption. Re-measure the prepared work and include a realistic allowance.
Check the current manufacturer calculator, product page and technical data before buying or mixing concrete.
Official bag calculator covering concrete mixes, post setting and other packaged products.
Open Official CalculatorOfficial product page listing package sizes and common general-purpose applications.
View Concrete MixManufacturer technical data including approximate bag yields, mixing and application information.
View Data SheetTechnical data and SDS links for current concrete and repair products.
Browse Technical Data