Concrete & masonry
Concrete Bag Calculator
Estimate whole 40, 50, 60 or 80 lb concrete bags, purchased yield, waste, dry weight and optional cost.
Estimated order quantity
0 bags to buy
- Bag yield
- Waste
- Bag yield and water demand vary by product and conditions; the exact package instructions control.
Planning estimate only. Verify product specifications, site conditions, and supplier purchase increments before ordering.
How many concrete bags do I need?
Multiply length by width by thickness in feet to obtain cubic feet. Add the selected waste allowance, divide by the published yield per bag, and round up because concrete mix is purchased in whole bags.
Volume with waste: volume × (1 + waste)
Bags to buy: round up(volume with waste ÷ yield per bag)
Worked example
A 10 × 10 ft pour at 4 inches thick contains 33.33 ft³. With 10% waste, plan for 36.67 ft³. An 80 lb bag yielding 0.60 ft³ requires 62 whole bags, providing 37.20 ft³.
40, 50, 60 and 80 lb bag yields
QUIKRETE currently publishes approximate yields of 0.30 ft³ for 40 lb, 0.375 ft³ for 50 lb, 0.45 ft³ for 60 lb and 0.60 ft³ for 80 lb Concrete Mix. Sakrete currently publishes the same 0.30, 0.45 and 0.60 ft³ yields for its 40, 60 and 80 lb High-Strength Concrete Mix. Mix designs differ, so use the yield printed on the selected bag.
Before buying bagged concrete
- Confirm minimum placement thickness, strength, water, mixing and curing requirements on the exact product.
- Use ready-mix pricing and delivery limits for larger pours; dozens of bags require substantial handling and mixer capacity.
- Verify forms, base preparation, reinforcement, joints, drainage, weather and local code separately.
- Do not add extra water beyond product instructions to make placement easier; excess water can reduce strength.
Current US manufacturer references: QUIKRETE Concrete Mix technical data sheet and Sakrete High-Strength Concrete Mix. Product documentation and project specifications control.
Concrete bag calculator FAQ
How many 80 lb bags are in one cubic yard?
At 0.60 ft³ per bag, one cubic yard (27 ft³) requires 45 bags before waste.
How many 60 lb bags are in one cubic yard?
At 0.45 ft³ per bag, one cubic yard requires 60 bags before waste.
Should I add waste?
A visible allowance helps cover uneven excavation, form variation and handling loss. Use measurements and site conditions to choose it rather than adding an unexplained margin.
Does this choose the right concrete mix?
No. It estimates quantity only. Strength, exposure, placement thickness and structural requirements must come from the plans, code and product instructions.