Concrete Bag Coverage Chart
How many square feet does one bag of concrete cover? This printable chart answers that question for every common bag size and slab thickness, so you buy the right number of bags at the hardware store.
What's on the Chart
The printable coverage chart shows all four standard bag sizes (40, 50, 60, and 80 lb) across five common slab thicknesses (2, 3, 4, 5, and 6 inches). Each cell tells you the square footage one bag covers at that thickness. The chart also includes bags-per-pallet counts so you can quickly estimate whether you need retail bags or a full pallet.
Coverage per Bag by Slab Thickness
| Bag Size | 2 in | 3 in | 4 in | 5 in | 6 in | Per Pallet |
|---|---|---|---|---|---|---|
| 40-lb bag | 1.8 ft² | 1.2 ft² | 0.9 ft² | 0.7 ft² | 0.6 ft² | 80 bags |
| 50-lb bag | 2.3 ft² | 1.5 ft² | 1.1 ft² | 0.9 ft² | 0.8 ft² | 56 bags |
| 60-lb bag | 2.7 ft² | 1.8 ft² | 1.4 ft² | 1.1 ft² | 0.9 ft² | 56 bags |
| 80-lb bag | 3.6 ft² | 2.4 ft² | 1.8 ft² | 1.4 ft² | 1.2 ft² | 42 bags |
Values assume standard-mix concrete at manufacturer-specified yield. Add 10% overage for waste, uneven subgrade, and form spillage.
Which Bag Size Should You Buy?
The 80-lb bag gives you the most concrete per dollar and per pallet, but each bag weighs 80 pounds. For small repairs and post holes, 50-lb bags are easier to handle and mix one at a time. The 40-lb bag exists primarily for minor patch jobs or for anyone who cannot safely lift heavier bags. The 60-lb bag is a middle ground but is less commonly stocked. Most hardware stores carry 80-lb bags of QUIKRETE or Sakrete on pallets at the best per-bag price. If you need more than 40–50 bags, compare the total cost to a ready-mix truck delivery (minimum ~1.5 cubic yards).
Bags vs. Ready-Mix: The Breakeven
As a rule of thumb, bagging concrete is practical up to about 0.5 cubic yards (roughly 14 bags of 80-lb mix). Between 0.5 and 2 cubic yards, it is worth calling for ready-mix quotes. Above 2 cubic yards, ready-mix is almost always cheaper, faster, and produces a more consistent pour. The chart on the printable includes a quick breakeven table so you can decide on-site.
Common Slab Thicknesses by Project
| Project | Typical Thickness | Notes |
|---|---|---|
| Patio / Walkway | 4 in | Standard for foot traffic and light furniture |
| Shed Pad | 4 in | Standard for lightweight structures |
| Driveway | 5 in | Thicker for vehicle weight; some codes require 6 in |
| Garage Floor | 5–6 in | Heavy slab for vehicle and equipment loads |
Need Exact Bag Counts?
This chart gives you quick estimates for a single bag. For a full project with specific dimensions, use the Concrete Calculator to get the exact number of bags (or cubic yards for ready-mix) including waste overage. For fence and deck posts, the Post Hole Calculator handles cylindrical holes and multiple post counts.