Bags of Concrete Per Yard

How bags-per-yard is calculated

A cubic yard of concrete equals 27 cubic feet. Bag yields are stated by the manufacturer: an 80 lb bag of Quikrete or Sakrete yields 0.60 cubic feet of mixed concrete, a 60 lb bag yields 0.45 ft³, and a 40 lb bag yields 0.30 ft³. To convert yards to bags, divide 27 by the bag yield. The result is then rounded up — you can't buy a partial bag, and you can't reuse a partial bag once it's been opened.

The math per cubic yard: 80 lb bags = ceil(27 / 0.60) = 45 bags. 60 lb bags = ceil(27 / 0.45) = 60 bags. 40 lb bags = ceil(27 / 0.30) = 90 bags. Add the waste allowance (default 10%) to get your order quantity: 50 bags of 80 lb, 66 bags of 60 lb, or 99 bags of 40 lb per cubic yard of finished concrete.

The bag-yield figures assume proper mixing — 80 lb bag with 1.2 gallons of water, mixed thoroughly to a uniform consistency with no dry pockets. Under-mixing reduces yield because dry cement stays packed; over-watering reduces strength without changing volume. A paddle mixer in a drill is the minimum tool for any job over 5 bags; a towable drum mixer ($40/day rental) is the minimum for jobs over 20 bags.

Choosing between 40, 60, and 80 lb bags

Bag weight is a trade-off between cost, handling, and mixing speed. Eighty-pound bags are the cheapest per cubic yard of finished concrete (typically $5–7 per bag at big-box stores as of 2026, working out to $7–10 per cubic yard of finished concrete before waste). But they're heavy — 80 pounds of dry mix plus a gallon of water is 88 pounds per bag, awkward for one person to lift into a mixer.

Sixty-pound bags cost about 15% more per cubic yard but are much easier to handle solo. They're the standard for residential DIY work — the sweet spot of cost and ergonomics. Most pros and serious DIYers default to 60 lb bags for any job over 10 bags. The cost premium is typically $1–2 per cubic yard, which is negligible.

Forty-pound bags are only economical for small repairs. They cost 30–40% more per cubic yard than 80 lb bags but are the only practical option if you're carrying concrete up stairs, through a narrow gate, or working alone without a mixer. They're also useful for small-batch work like setting a single fence post or patching a sidewalk crack. For any job over 10 bags, switch to 60 or 80.

The waste allowance (10% default) covers spillage, uneven subgrade, and the rounding-up needed to make bag counts work in practice. If you have laser-leveled forms and careful mixing technique, drop the slider to 5%. For first-time DIYers on uneven ground, 15% is more realistic. The slider lets you tune this per job.

When to switch from bags to ready-mix

The crossover point is around 1.5–2 cubic yards. Below that, bags win on cost and convenience — you can mix on your own schedule, work alone, and don't need a pump truck or delivery coordination. Above 2 yards, ready-mix is almost always cheaper per cubic yard of finished concrete, and dramatically less labour.

Ready-mix pricing varies by region and distance from the batch plant. As of 2026, ready-mix delivered runs $130–180 per cubic yard in most US markets, with a short-load fee ($150–300) for orders under 3 yards and a small-load fee ($75–150) for orders under 1 yard. So 1 yard of ready-mix might cost $275–325 delivered ($145 concrete + $180 short-load fee), while 1 yard in bags costs $325–450 plus 4 hours of mixing labour.

For 3+ yards, ready-mix is the obvious choice. For 5+ yards, you can also negotiate delivery time windows, batch adjustments (air entrainment, accelerators), and pump service. The cost per yard drops sharply above 8 yards because that's a full truckload — no short-load fees.

There's a hidden labour cost to bagged concrete that doesn't show up in any calculator. Mixing 60 eighty-pound bags (1 yard) takes a fit adult 4–5 hours with a towable mixer, or 8+ hours by hand. Concrete has a working time of 30–60 minutes once mixed — meaning you cannot mix all 60 bags and then start pouring. You're racing against set time on every batch. For any job where you'd be mixing 50+ bags, get a ready-mix quote first.

What the bag-count calculator excludes: water (figure 1 gallon per 80 lb bag, so 60 gallons for a yard), mixing equipment (towable mixer $40/day, paddle mixer $25/day, wheelbarrow $40 purchase), and finishing tools (mag float, edger, broom — $50 kit). Bagged concrete also produces 5–10% more waste than ready-mix because of partial-bag leftovers, which the 10% waste allowance is designed to cover.