How Much Concrete for a 3x20 Sidewalk?
How much concrete for a 3x20 sidewalk: about 0.74 cubic yards at the standard 4-inch thickness. The walk covers 60 square feet, so each extra inch of depth adds about 0.19 yards.
Concrete calculator →Step-by-step
- Area: 3 × 20 = 60 sq ft.
- Volume: 60 × (4 ÷ 12) = 20.0 cu ft.
- Yards: ÷ 27 = 0.74 yd³.
- Bags instead: 34 bags of 80 lb mix (45 of 60 lb).
Related: How Much Gravel for a 3x20 Walkway?
Concrete by thickness
| Thickness | Cubic feet | Cubic yards | Yards +10% | 80 lb bags | 60 lb bags |
|---|---|---|---|---|---|
| 4 in | 20.0 | 0.74 | 0.81 | 34 | 45 |
| 5 in | 25.0 | 0.93 | 1.02 | 42 | 56 |
| 6 in | 30.0 | 1.11 | 1.22 | 50 | 67 |
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 3x20 Walkway?
Joints along the walk
Tool a control joint about every 3 feet, matching the width, which gives roughly 6 joints along this walk. Add an isolation joint where the walk meets the house, steps or a driveway so the slabs can move independently.
Truck, bags or a short load
At 0.74 yards, bags are realistic for a patient crew. Long walks are often poured in sections, so ask the plant how long the truck can wait and whether there is a short-load fee.
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 3x20 sidewalk?
About 0.74 cubic yards at 4 inches thick.
How many bags for a 3x20 sidewalk?
About 34 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 many 80 lb bags make a cubic yard?
About 45. Each 80 lb bag yields roughly 0.6 cubic feet, and a cubic yard is 27 cubic feet.
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 3x10 Sidewalk?
- How Much Concrete for a 6x75 Sidewalk?
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