CALCULATOR · FREE免费 · Free
Concrete Calculator
Enter the slab length, width and thickness to estimate concrete volume and the number of 60 lb or 80 lb bags.
--Concrete volume · cu yd
--60 lb bags · bags
--80 lb bags · bags
Estimates only; verify on site before ordering or building.
Example
| Item | Value | Unit |
|---|---|---|
| Length | 10 | ft |
| Width | 10 | ft |
| Thickness | 4 | in |
| Concrete volume | 1.3 | cu yd |
| 60 lb bags | 78 | bags |
| 80 lb bags | 59 | bags |
Where people go wrong
- Entering inches where feet are expected makes the result 12 times too large.
- Skipping the waste allowance; most pours need 5 to 10 percent extra.
- Bagged concrete and ready-mix are ordered differently; confirm before you buy.
FAQ
How many 60 lb bags are in a cubic yard?
About 60 bags. A 60 lb bag yields about 0.45 cu ft and a cubic yard is 27 cu ft.
Why add 5 percent waste?
Uneven ground, edge spill and mixing loss all consume extra material; 5 percent is a conservative starting point.