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Concrete Bag Calculator

One question, one answer. Enter a volume — or the slab dimensions if you have not worked it out yet — and get the bag count for every common size at once: 40, 50, 60, 80 and 90 lb, plus 20 kg and 25 kg. Brand makes almost no difference; Quikrete, Sakrete, Blue Circle and Hanson all yield within a few per cent of each other.

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How many bags for your concrete volume
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What a bag of concrete actually yields

Bag size Yield per bag Bags per ft³ Bags per yd³ Bags per m³
40 lb 0.30 ft³ (0.0085 m³) 3.3 90 118
50 lb 0.375 ft³ (0.0106 m³) 2.7 72 95
60 lb 0.45 ft³ (0.0127 m³) 2.2 60 79
80 lb 0.60 ft³ (0.0170 m³) 1.7 45 59
90 lb 0.68 ft³ (0.0193 m³) 1.5 40 52
20 kg 0.0093 m³ (0.33 ft³) 3.0 82 108
25 kg 0.0116 m³ (0.41 ft³) 2.4 66 86

Those are pre-mixed concrete yields — cement, sand and aggregate already in the bag, just add water. Regional preferences differ: the US runs on 60 and 80 lb bags, the UK on 20 and 25 kg, and most of Europe on 25 kg with 30 and 40 kg sacks in some countries. Always round up, and always check the printed yield if you are buying an unfamiliar brand.

The point where bags stop making sense

Bagged concrete costs roughly double ready-mix per unit volume. What you are paying for is convenience and the ability to buy exactly seven bags on a Saturday morning. That trade is worth it right up until the moment it isn’t:

  • Under 0.4 m³ / 0.5 yd³ (about 30 bags of 80 lb) — bags win easily. No delivery minimum, no waiting window, mix as you go.
  • 0.4 to 0.75 m³ — borderline. You want a mixer at this scale. Volumetric trucks, which bill only for what they discharge, compete well here.
  • Over 0.75 m³ / 1 yd³ — ready-mix, every time. Forty-five bags is 1.6 tonnes of lifting, tearing and mixing before you place a single barrow.

There is also a quality argument. Every bag you mix by hand is a separate batch with its own water content. Ready-mix is one consistent batch, weighed at the plant.

Frequently asked questions

How many 80 lb bags of concrete are in a yard?

45. One 80 lb bag yields 0.60 ft³ and a cubic yard is 27 ft³, so 27 ÷ 0.6 = 45.

How many 60 lb bags in a yard?

60 bags. At 40 lb it is 90 bags, at 50 lb it is 72.

How many 25 kg bags in a cubic metre?

About 86 bags of pre-mixed concrete — over two tonnes of bags for a single cubic metre. Price up ready-mix before committing to that.

How many bags of concrete on a pallet?

42 × 80 lb, 56 × 60 lb or 80 × 40 lb in the US; UK merchants typically stack 40 to 56 × 25 kg. A US pallet works out at roughly 0.93 cubic yards whichever size you pick. There is more detail in our pallet guide.

How many bags for a 10×10 slab?

At 4 inches thick: 56 × 80 lb, 74 × 60 lb, or 112 × 40 lb. That is 1.23 cubic yards before wastage — comfortably into ready-mix territory.

How much water goes in a bag of concrete?

Around 2.8 litres (3 quarts) for an 80 lb bag, 2 litres for a 60 lb, and 2 to 2.5 litres for a 25 kg bag. Follow the printed instruction and err dry. Excess water is the single biggest cause of weak hand-mixed concrete.

How much does a bag of concrete cost?

$5 to $8 for an 80 lb bag in the US, £5 to £8 for a 25 kg bag in the UK at 2026 prices. Compare that against delivered ready-mix in the cost calculator.

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