How much concrete do I need for a sidewalk?
Every 10 feet of a 4 ft wide, 4 inch thick sidewalk takes about 25 bags of 80 lb concrete, including 10% extra. A 30 ft walk takes 74 bags of 80 lb.
Per 10 feet of walk, 4 inches thick, with 10% extra:
| Width | Concrete | Bags of 80 lb | Bags of 60 lb |
|---|---|---|---|
| 3 ft wide | 11 cu ft | 19 bags | 25 bags |
| 4 ft wide | 14.7 cu ft | 25 bags | 33 bags |
| 5 ft wide | 18.3 cu ft | 31 bags | 41 bags |
Tips
- Pour in sections between forms and cut control joints about every 4 to 5 feet (roughly the walk’s width) so cracks form in the joints.
- A compacted gravel base under the slab stops it settling unevenly.
- Long walks add up fast: 45 bags make a cubic yard, the point where ready-mix usually costs less.