Quantity · Bagged concrete
Concrete Bag Calculator (Sakrete & Quikrete)
How many 40–80 lb bags you need for a pad, step, or small slab — with waste built in, and a clear tip when ready-mix becomes the smarter order.
Project dimensions
Yields match typical Sakrete / Quikrete high-strength mixes. Check the bag label — lightweight and mortar mixes differ.
Bags to buy
62
× 80 lb · 0.6 cu ft each
- Volume (raw)
- 33.33 cu ft
- With waste
- 36.67 cu ft
- Cubic yards
- 1.36 cy
Over ~1 cy (about 62× 80 lb bags) — ready-mix is usually cheaper and far less mixing. Check the ready-mix and cost calculators.
Breakdown
- 10 × 10 × (4 ÷ 12) = 33.33 cu ft
- × (1 + 10% waste) = 36.67 cu ft
- ÷ 0.6 cu ft/bag = 61.1 → buy 62
Price data updated . National US ranges from published supplier and contractor averages. Not a bid. Local quotes vary.
How this Sakrete / Quikrete calculator works
Bag counts are volume divided by yield. Brands differ slightly; the table below uses standard high-strength bag yields common on US shelves.
cu ft = length × width × (thickness_in ÷ 12) with waste = cu ft × (1 + waste %) bags = ceil(with waste ÷ yield_per_bag)
Worked example. An 80 lb bag yields about 0.60 cu ft. A 3 × 3 ft × 4 in pad is 3 cu ft → 5 bags before waste, or 6 bags at 10% waste. Above ~1 cy, compare to ready-mix.
Bag yields (Sakrete / Quikrete class)
Yields vary by brand and water; these are the planning numbers used in the calculator.
| Bag | Yield (cu ft) |
|---|---|
| 40 lb | 0.30 |
| 50 lb | 0.375 |
| 60 lb | 0.45 |
| 80 lb | 0.60 |
- Above ~1 cubic yard, ready-mix is usually cheaper than bags.
Concrete Bag calculator (Sakrete & Quikrete) FAQ
- How many Sakrete or Quikrete bags do I need?
- Find the volume in cubic feet (length × width × thickness in feet), add waste, then divide by the yield on the bag. An 80 lb high-strength bag typically yields about 0.60 cubic feet; a 60 lb bag about 0.45. Always read the label — the brand name on the store shelf may use the same yields.
- Should I buy 40 lb, 60 lb, or 80 lb bags?
- 80 lb bags give more concrete per trip to the mixer and are the usual choice for pads and small slabs. 60 lb and 40 lb bags are easier to lift. Yield drops with bag weight — this calculator switches yield when you change size.
- How much water do I add per bag?
- Follow the printed range on the bag. Too much water weakens the mix; too little leaves dry pockets. Mix one bag fully before starting the next so every batch has the same consistency.
- Does this Sakrete calculator work for Quikrete too?
- Yes for standard high-strength concrete mixes with the yields in the table below. Mortar, thin-set, and lightweight mixes are different products — do not use these yields for them.