/// Order-ready concrete estimate

Concrete Calculator for Cubic Yards and Bags

Use this concrete calculator to estimate cubic feet, cubic yards, and 40, 50, 60, or 80 lb bags for rectangular or circular pours. Add multiple areas, enter depth, and apply a project-specific waste allowance. Bag counts use published QUIKRETE Concrete Mix No. 1101 yields and round up to whole bags before you prepare a supplier list.

Content reviewed Jul 15, 2026 · Source records reviewed through Jul 15, 2026

01

Project areas

Add every pour area, choose a shape, and enter finished dimensions. Depth is entered in inches or centimeters.

01 / Area 1
ft
ft
in
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USDOptional — from your quote, not a live feed
View current estimate

/// Answer-first planning notes

How many cubic yards and bags of concrete do I need?

Published QUIKRETE Concrete Mix No. 1101 package yields
Planning inputCalculation roleCheck before ordering
40 lbApproximately 0.30 ft³QUIKRETE No. 1101-40 onlySources: The QUIKRETE Companies, LLC
50 lbApproximately 0.375 ft³QUIKRETE No. 1101-50 onlySources: The QUIKRETE Companies, LLC
60 lbApproximately 0.45 ft³QUIKRETE No. 1101-60 onlySources: The QUIKRETE Companies, LLC
80 lbApproximately 0.60 ft³QUIKRETE No. 1101-80 onlySources: The QUIKRETE Companies, LLC

/// Formula & field notes

How this concrete estimate works

FormulaRectangular volume = length × width × depth. Circular volume = π × (diameter ÷ 2)² × depth. Adjusted volume = base volume × (1 + waste %).

Worked example

A 10 ft × 10 ft slab at 4 in deep equals 1.2346 yd³. With 10% waste it becomes 1.3580 yd³, or 62 bags when each 80 lb bag yields about 0.60 ft³.

/// Source trail

Data & assumptions

Every source has a declared scope. A reference can support a conversion or product assumption without turning this estimate into a supplier quote.

National Institute of Standards and Technology · Primary evidenceNIST Guide to the SI, Appendix B: Conversion Factors

Exact international-foot to meter conversion; U.S. survey-foot conversion is explicitly outside this claim.

Effective 2025-08-18 · Reviewed 2026-07-15 · Next review 2027-07-15
NOAA National Geodetic Survey · Prequalified fallbackThe DSDATA Format, Appendix D: U.S. Survey Foot vs International Foot

Independent confirmation that one international foot equals exactly 0.3048 meters; U.S. survey-foot conversion remains distinct.

Effective 2025-06-10 · Reviewed 2026-07-15 · Next review 2027-07-15
The QUIKRETE Companies, LLC · Primary evidenceQUIKRETE Concrete Mix No. 1101-40 product yield

Approximate 0.3 ft³ yield for the 40 lb QUIKRETE Concrete Mix No. 1101-40 package only; not a generic bag-yield assumption.

Effective 2022-10-26 · Reviewed 2026-07-15 · Next review 2026-09-13
The QUIKRETE Companies, LLC · Primary evidenceQUIKRETE Concrete Mix No. 1101-50 product yield

Approximate 0.375 ft³ yield for the 50 lb QUIKRETE Concrete Mix No. 1101-50 package only; not a generic bag-yield assumption.

Effective 2022-10-26 · Reviewed 2026-07-15 · Next review 2026-09-13
The QUIKRETE Companies, LLC · Primary evidenceQUIKRETE Concrete Mix No. 1101-60 product yield

Approximate 0.45 ft³ yield for the 60 lb QUIKRETE Concrete Mix No. 1101-60 package only; not a generic bag-yield assumption.

Effective 2022-10-26 · Reviewed 2026-07-15 · Next review 2026-09-13
The QUIKRETE Companies, LLC · Primary evidenceQUIKRETE Concrete Mix No. 1101-80 product yield

Approximate 0.6 ft³ yield for the 80 lb QUIKRETE Concrete Mix No. 1101-80 package only; not a generic bag-yield assumption.

Effective 2022-10-26 · Reviewed 2026-07-15 · Next review 2026-09-13

/// Common questions

Concrete calculator FAQ

How much extra concrete should I order?

Use a project-specific allowance for irregular excavation, compaction, spillage, cuts, and supplier minimums. ProjectQty starts at zero instead of guessing; enter the allowance your plan or supplier supports, then confirm the final cubic yards or bags.

Is the result a supplier quote?

No. ProjectQty calculates quantities from your dimensions and assumptions. Prices are optional user inputs, not live local quotes, and delivery, taxes, minimum loads, and labor are not included unless you add them separately.

Can I use metric measurements?

Yes. Switch to Metric before entering measurements. ProjectQty normalizes the geometry internally and shows the most useful ordering units for the selected material.