Concrete Sidewalk Calculator
Enter the length, width and thickness of your walkway. For a path with turns, add each straight run as its own area.
Last updated November 13, 2026
How much concrete for a sidewalk?
A sidewalk is a long slab: volume = length × width × thickness.
Example: a 50 ft walk, 4 ft wide and 4 inches thick is 50 × 4 × 0.333 = 66.7 cubic feet, or 2.47 cubic yards.
Cubic yards by length and width
All figures are 4 inches thick with no waste added.
| Length | 3 ft wide | 4 ft wide | 5 ft wide | 6 ft wide |
|---|---|---|---|---|
| 10 ft | 0.37 | 0.49 | 0.62 | 0.74 |
| 25 ft | 0.93 | 1.23 | 1.54 | 1.85 |
| 50 ft | 1.85 | 2.47 | 3.09 | 3.70 |
| 100 ft | 3.70 | 4.94 | 6.17 | 7.41 |
Short walks with bags
A 3 ft × 10 ft walk is 10 cubic feet, which is 17 bags of 80 lb mix. Up to about 25 ft of 3 ft walk stays under a cubic yard, where bags are still practical. See the concrete bag calculator.
Joints and curves
- Control joints are commonly cut at spacings close to the width of the walk. They do not change the volume.
- For a curved walk, measure along the centerline and use that as the length.
- Where the walk meets a driveway, add the thicker section as a separate area.
Frequently asked questions
How much concrete do I need for a sidewalk?
Multiply length × width × thickness in feet and divide by 27. A 50 ft walk, 4 ft wide and 4 inches thick is 2.47 cubic yards.
How thick should a concrete sidewalk be?
Four inches is the usual thickness for a walkway. Where vehicles cross it, such as at a driveway, it is commonly made thicker.
How wide should a sidewalk be?
Three feet suits a single path to a door. Four to five feet lets two people walk side by side. Public sidewalks follow local standards.
How many bags for a 3 ft by 10 ft walkway?
At 4 inches thick it is 10 cubic feet, which is 17 bags of 80 lb mix, or 19 with 10% for waste.