Bags needed
0 80 lb bags
Your slab
Every bag size
| Bag size | Bags / yd | Bags needed |
|---|
How many bags of concrete do you need?
This bags-of-concrete calculator works for QUIKRETE, Sakrete and any pre-mixed brand. Bags are sized by weight, and each weight yields a known volume once mixed:
| Bag size | Yield (mixed) | Bags per cubic yard |
|---|---|---|
| 40 lb | ~0.30 cu ft | 90 |
| 50 lb | ~0.375 cu ft | 72 |
| 60 lb | ~0.45 cu ft | 60 |
| 80 lb | ~0.60 cu ft | 45 |
To find your bag count, calculate the pour volume in cubic feet and divide by the yield. Need the full picture — cubic yards, ready-mix and multiple shapes? Use the main concrete calculator, or convert any volume with the cubic yards calculator.
Frequently asked questions
How many bags of concrete do I need?
Work out the volume of your pour in cubic feet (length x width x thickness, all in feet), then divide by the yield of your bag: an 80 lb bag makes about 0.60 cu ft, a 60 lb bag ~0.45 cu ft, a 50 lb bag ~0.375 cu ft and a 40 lb bag ~0.30 cu ft. This calculator does it for every bag size at once and adds a waste allowance.
How many 80 lb bags of concrete are in a cubic yard?
About 45. There are 27 cubic feet in a cubic yard, and an 80 lb bag yields ~0.60 cu ft, so 27 / 0.60 = 45 bags. A 60 lb bag (0.45 cu ft) takes 60 bags per yard, a 50 lb bag (0.375 cu ft) takes 72, and a 40 lb bag (0.30 cu ft) takes 90.
How many bags of concrete for a 10x10 slab?
A 10 ft x 10 ft slab at 4 inches thick is about 33.3 cubic feet. That is roughly 56 x 80 lb bags, 74 x 60 lb bags, or 111 x 40 lb bags before waste — add about 10% to be safe. At that size, ready-mix is usually cheaper than bags.
How many bags of concrete for a fence post?
For a typical 4-inch post in a 10-inch-diameter hole 2 feet deep, you need about 1.1 cu ft of concrete after subtracting the post — roughly two 60 lb or 50 lb bags per hole. Enter the hole as a column (diameter and depth) in the main concrete calculator to get an exact figure.
When is it cheaper to order ready-mix instead of bags?
Roughly once you pass one cubic yard (about 45 x 80 lb bags). Below that, bags are convenient and there is less waste; above it, a ready-mix truck is usually cheaper per yard and much less work than mixing dozens of bags.
How much does a bag of concrete cover?
At a 2-inch thickness, an 80 lb bag covers about 3.6 sq ft, a 60 lb bag about 2.7 sq ft, and a 40 lb bag about 1.8 sq ft. Coverage halves if you double the thickness. Enter a price per bag above to also estimate your total cost.
How much do 20 bags of concrete cost?
Pre-mixed concrete typically costs about $4-$7 for a 60 lb bag and $5-$9 for an 80 lb bag, so 20 bags run roughly $80-$180 depending on size, brand and region. Enter a price per bag above and this calculator adds up your exact total. For large jobs, compare against ready-mix, which is usually cheaper per cubic yard.
How many bags of concrete for a 1000 sq ft slab?
A 1,000 sq ft slab at 4 inches thick is about 333 cubic feet, or roughly 12.3 cubic yards. That would take about 555 x 80 lb bags (or 740 x 60 lb bags) — completely impractical to mix by hand. For a slab this size, order ready-mix from a truck instead of bags; a full truck carries about 10 cubic yards.
How many 80 lb bags of concrete are on a pallet?
Most suppliers ship 80 lb concrete mix 42 bags to a pallet (about 3,360 lb), while 60 lb bags usually come 56 to a pallet and 40 lb bags 80 to a pallet. Pallet counts vary slightly by brand and store, so confirm with QUIKRETE, Sakrete or your local yard before ordering full pallets.