60-lb vs. 80-lb concrete bags

Why the rounded weights differ

The target volume is 29.7 cubic feet. Dividing by 0.45 gives exactly 66 bags; dividing by 0.60 gives 49.5, which rounds to 50. Whole-bag rounding creates the small difference in purchased dry weight.

Compare cost by yield

Divide the bag price by the product yield to compare dollars per cubic foot. Then multiply each option’s whole-bag quantity by its actual bag price. A lower price per bag is not necessarily the cheaper way to fill the same space.

Consider handling and mixing

Smaller bags may be easier to move, while larger bags reduce the number to open and handle. Check your mixer’s capacity and the product’s mixing directions. Water additions and working time are product-specific; do not infer them from the calculator.

Example: price per cubic foot

Suppose a 60-lb bag costs $5.50 and an 80-lb bag costs $7.00. Dividing by yield gives about $12.22 per cubic foot for the 60-lb bag and $11.67 for the 80-lb bag. For 1 cubic yard plus 10%, that is 66 × $5.50 = $363 versus 50 × $7.00 = $350. These prices are arithmetic examples only; use the shelf prices where you buy.

Small jobs: rounding matters more

For a 2-cubic-foot job, 60-lb bags round up to 5 bags (2.25 ft³ purchased) and 80-lb bags round up to 4 bags (2.40 ft³ purchased). On small volumes, the bag size that leaves less unused product can be the cheaper choice even if its price per cubic foot is higher. Run both yields through the bag calculator before buying.

Product reference: QUIKRETE concrete mix technical data. Confirm the current label for your chosen product.

MaterialScope editorial · Updated September 29, 2026 · Calculation methodology