How Much Concrete for a 3x100 Sidewalk?
How much concrete for a 3x100 sidewalk: about 3.70 cubic yards at the standard 4-inch thickness. The walk covers 300 square feet, so each extra inch of depth adds about 0.93 yards.
Concrete calculator →Step-by-step
- Area: 3 × 100 = 300 sq ft.
- Volume: 300 × (4 ÷ 12) = 100.0 cu ft.
- Yards: ÷ 27 = 3.70 yd³.
- Bags instead: 167 bags of 80 lb mix (223 of 60 lb).
Related: How Much Gravel for a 3x100 Walkway?
Concrete by thickness
| Thickness | Cubic feet | Cubic yards | Yards +10% | 80 lb bags | 60 lb bags |
|---|---|---|---|---|---|
| 4 in | 100.0 | 3.70 | 4.07 | 167 | 223 |
| 5 in | 125.0 | 4.63 | 5.09 | 209 | 278 |
| 6 in | 150.0 | 5.56 | 6.11 | 250 | 334 |
Thickness for walks
Four inches is the usual thickness for a residential walk that only sees foot traffic. Where the walk crosses a driveway, pour that section at 6 inches, since car tires will cross it.
Related: How Much Pea Gravel for a 3x100 Walkway?
Joints along the walk
Walks are usually jointed every 4 to 6 feet, often at a spacing equal to the walk width, so a 3-foot walk gets a joint about every 3 feet: roughly 32 joints over 100 feet. Square panels crack less than long, thin ones.
How to buy it
This is past the point where bags are practical; call a ready-mix plant. If the truck cannot reach the far end of the walk, plan for wheelbarrows or a chute extension; see how far a concrete chute reaches.
Slope and finish
Give the walk a slight cross slope, around 1/4 inch per foot, so water sheds to one side. A light broom finish across the walk gives grip when it is wet.
Questions people ask
How many yards of concrete for a 3x100 sidewalk?
About 3.70 cubic yards at 4 inches thick.
How many bags for a 3x100 sidewalk?
About 167 bags of 80 lb concrete at 4 inches.
How thick should a sidewalk be?
Four inches for foot traffic, 6 inches where vehicles cross.
How far apart should sidewalk joints be?
About every 3 feet for a 3-foot-wide walk, keeping panels close to square.
How thick should the base under the slab be?
About 4 inches of compacted gravel is common for residential slabs, more on soft or poorly drained soil.
Related guides
- Concrete Sidewalk Thickness for Walks and Crossings
- How Much Concrete for a Sidewalk? Yards per Foot
- How Much Area Does a Yard of Concrete Cover?
- How Many Bags of Concrete in a Yard? 40, 60, 80 lb
- Gravel Base Under a Concrete Slab: Depth and Tons
- How Many Yards in a Concrete Truck? Mixer Sizes
- Concrete Short Load Fee: What It Is and How to Cut It
- 60 lb vs 80 lb Concrete Bags: Yield, Count, and Cost
- Rebar vs Wire Mesh in a Slab: Which One to Use
- How Much Concrete for a 3x60 Sidewalk?
- How Much Concrete for a 3x75 Sidewalk?
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