Concrete · US units

Concrete Calculator — Bags vs Cubic Yards

An 80 lb bag yields 0.60 cubic feet; a 60 lb bag yields 0.45. That is Quikrete Concrete Mix 1101 (revised October 2022) and Sakrete High-Strength TDS, not a forum round-number. 27 ÷ 0.60 = 45 bags per cubic yard.

Basket 2026-08-27

Slab

Bags to buy

112 bags

66.667 cu ft net · 2.469 yd³ · 80 lb

$669.76

Exact bags: 111.111
Yield / bag: 0.6 cu ft
Bags / yd³: 45
Ready-mix (if priced): enter $/yd³

Short-load fees can erase a ready-mix advantage on small slabs. Compare your plant quote to the bag total; we will not invent a plant price.

What calculator.net does not show

Quikrete’s own method is: compute volume, divide by bag yield, round up to the next bag. There is no official waste percentage. The 10% toggle here is optional and labelled. Ready-mix dollars are worse: there is no official 2026 NRMCA national price in this basket. Secondary blogs quote about $125–$195 per cubic yard — unofficial. FRED series WPU1333 for July 2026 is 394.468; that is a producer price index, not dollars per yard.

Worked US example: 10×20 slab, 4 inches thick

Volume    = 10 × 20 × (4 ÷ 12) = 66.667 cu ft
          = 66.667 ÷ 27 = 2.469 yd³
80 lb bags = 66.667 ÷ 0.60 = 111.111 → buy 112 bags
Cost @ $5.98 (HD 110180, 2026-08-27) = 112 × $5.98 = $669.76
60 lb bags = 66.667 ÷ 0.45 = 148.148 → buy 149 bags
Cost @ $4.48 (HD 110160) = 149 × $4.48 = $667.52
Optional 10% convention = 73.333 cu ft → 123 bags of 80 lb

A 2.5 yard truck looks cheaper on a blog $/yd³ until the plant adds a short-load fee. Leave ready-mix blank unless you have a quote. Gravel in the index is a 50 lb bag at $6.50 covering 0.5 cu ft — not a cubic foot of base.

Citations

The Quikrete Companies. QUIKRETE Concrete Mix product data (No. 1101). Accessed 2026-08-27. https://www.quikrete.com/pdfs/data_sheet-concrete%20mix%201101.pdf — Revised October 2022. An 80 lb bag yields approximately 0.60 ft³; a 60 lb bag yields approximately 0.45 ft³. The published calculator method is divide volume by yield and round up to the next bag — no waste percentage.
Sakrete. Sakrete High-Strength Concrete Mix technical data sheet. Accessed 2026-08-27. https://www.sakrete.com/wp-content/uploads/2024/01/Sakrete-High-Strength-Concrete-Mix-TDS.pdf — 80 lb bag yield 0.6 ft³; 60 lb bag 0.45 ft³. Confirms the same 80 lb / 0.60 ft³ industry bag used in the Quikrete 1101 sheet.
FRED, Federal Reserve Bank of St. Louis. Producer Price Index by Commodity: Nonmetallic Mineral Products: Concrete Ingredients and Related Products (WPU1333). Accessed 2026-08-27. https://fred.stlouisfed.org/series/WPU1333 — July 2026 value 394.468. This is an index number, not dollars per cubic yard. There is no official 2026 NRMCA national $/yd³ in this basket.
Secondary cost blogs (not NRMCA). Unofficial 2026 ready-mix blog bands. Accessed 2026-08-27. https://latestcost.com/price-ready-mix-concrete-across-u-s-markets/ — Secondary blogs circulating in 2026 quote roughly $125–$195 per cubic yard for standard residential mix. Not an official NRMCA figure. Shown only as a labelled unofficial planning band; the field stays user-editable.

These calculators estimate material takeoff for planning. They are not engineering, structural, or code advice. Confirm spans, mixes, fastener schedules, and permits with a licensed professional and the manufacturer’s current data sheet. Local shelf prices and tax are not this index.