Concrete bag yields
How much placed concrete you get from a bag, by weight and mix type. An 80 lb bag yields 0.60 ft³ (0.017 m³); the number scales at a fixed rate per pound, which is the part the chart on the bag leaves out.
01 How the math works
Yield is the placed volume of concrete you get from one bag of dry mix once it is mixed with water and consolidated. It is a lookup off the product data sheet, but the numbers are not arbitrary. For standard normal-weight mixes the yield tracks a single constant: 0.0075 ft³ of placed concrete per pound of dry mix. Multiply by the bag weight and you have the yield.
Bags per cubic yard = 27 ft³ ÷ yield per bag
Bags for a pour = volume ÷ yield per bag, × (1 + waste), rounded up
That constant is why the three chart rows line up: 40 lb → 0.30 ft³, 60 lb → 0.45 ft³, 80 lb → 0.60 ft³. It also carries past the chart. A 50 lb fast-setting bag reads 0.375 ft³ off the same rate, and any bag weight you can find converts the same way. The yield on the bag is the amount you get when the batch goes to plan, which is also how the manufacturer quotes it.
The full yield table, both units — standard mix is Quikrete No. 1101 and Sakrete Concrete Mix (identical published yields); fast-setting is Quikrete No. 1004; countertop is Quikrete No. 1106-80:
02 Worked example
Take one cubic yard — 27 ft³ (0.76 m³), the quantity ready-mix is sold by and the natural unit to compare bag sizes against.
In 80 lb standard bags at 0.60 ft³ each, that yard is 45 bags (27 ÷ 0.60). In 60 lb bags it is 60 bags; in 40 lb bags, 90 bags. The bag count triples across the range, but the mix does not: every one of those buys is 3,600 lb (1,633 kg) of dry product, because 27 ft³ ÷ 0.0075 ft³/lb is 3,600 lb no matter how it is packaged. A cubic metre works the same way — 59 bags of 80 lb standard, since 1 m³ is 35.31 ft³.
Set the lookup to 80 lb standard with a volume of 27 ft³ and it returns the 45-bag order and the 3,600 lb dry weight directly.
03 When this reference is wrong
The yield figure is a placed maximum under a good batch, and three things move a real order off it.
- The number is an "approximately." Data sheets quote the fast-set bag as approximately 0.375 ft³ for a reason — placed yield depends on full consolidation and on stopping at the mixing water the bag calls for. Over-water the batch and the extra volume is water that bleeds off, not concrete. Treat the listed yield as a ceiling and add the waste factor rather than shaving it.
- Yield is per product, not per bag weight. The 0.0075 ft³/lb rate holds for standard normal-weight mixes, and Quikrete's fast-setting and countertop mixes happen to sit on it too. Lightweight, self-leveling, and high-flow specialty mixes do not — their dry density is different, so an 80 lb bag of a self-leveling underlayment will not place 0.60 ft³. Read that product's own data sheet; do not carry the standard number across.
- The brand is not the variable. Quikrete and Sakrete publish the same standard-mix yields — 0.60 ft³ per 80 lb bag on both. What changes the number under a single brand is the product: a "high-strength," "crack-resistant," or fast-setting variant is a different mix with its own sheet. Check the product number stamped on the bag, not the logo.
04 What to do with the result
Under about 1 yd³ (0.76 m³), bagged premix is the right call — take the bag count above, add the waste factor, and round up. Above that, bags stop making sense. A cubic yard is 45 bags of 80 lb premix, 3,600 lb to lift, cut, mix, and place inside the roughly 90 minutes of working time before the batch sets. Ready-mix is cheaper per yard and more uniform there, and the short-load fee most US suppliers charge under 2 yd³ — typically $50 to $150 — is recovered before you have finished the second bag. The exception is access: a backyard, basement, or balcony a truck cannot reach makes bags the only option regardless of volume.
When you are staying with bags, the yield-per-pound constant means the bag size is a handling choice, not a cost one — the same cubic yard is 45 heavy bags or 90 light ones for the same 3,600 lb of mix. Pick the size that matches how many trips and how much lifting you want, and order to the placed volume you measured, not the raw dimensions.
05 Common questions
- How much concrete does an 80 lb bag make?
- An 80 lb bag of standard mix yields 0.60 ft³ (0.017 m³) of placed concrete. A 60 lb bag yields 0.45 ft³, a 40 lb bag 0.30 ft³ — a constant 0.0075 ft³ per pound of dry mix.
- How many bags of concrete make a cubic yard?
- 45 bags of 80 lb, 60 bags of 60 lb, or 90 bags of 40 lb. The count changes with bag size, but each is 3,600 lb of dry mix for the yard.
- Do Quikrete and Sakrete have the same yield?
- For their standard concrete mix, yes — both publish 0.60 ft³ per 80 lb bag. Yield is set by the mix, not the brand. A specialty or fast-setting product from either has its own figure on its own data sheet.
- How many 80 lb bags are in a cubic metre?
- 59 bags of 80 lb standard mix. A cubic metre is 35.31 ft³, and 35.31 ÷ 0.60 is 58.9, rounded up to 59.
- Does a fast-setting bag yield the same?
- A 50 lb fast-setting bag yields 0.375 ft³ — the same 0.0075 ft³ per pound as standard mix, just in a lighter bag. That works out to 72 bags per cubic yard.