Concrete Sidewalk Calculator
A 30-foot residential sidewalk (4 ft wide, 4 in thick) needs about 1.5 cubic yards of concrete — roughly 74 bags of 80-lb mix including waste. Enter your dimensions below to get the exact volume, bag count, and cost estimate for your walkway.
Pro Tips
- →Sidewalks should be 4 inches thick for residential use
- →Standard width is 4-5 feet for comfortable walking
- →Add control joints every 4-5 feet to prevent random cracking
- →Slope slightly for water drainage (1-2%)
- →Use 4 inches of compacted gravel as a base
Includes 10% waste factor
That's typically a professional pour. See costs ↓
4 short emails from Dave: what a fair quote should land at for your slab, the scope changes that swing it ±$500, and whether DIY is actually cheaper at your volume. Reply anytime — he'll review your real quote.
Cost Estimate
Estimated material costs for your project
Recommendation: Ready-Mix Concrete
For projects over 1 cubic yard, ready-mix is typically more economical and easier to work with.
74 bags × 80lb
1.63 cubic yards + delivery
120 sq ft × $3.00–$8.00/sq ft
Prices vary by location and time. Contact local suppliers for accurate quotes.
For general step-by-step instructions, read our complete Sidewalk Thickness and How To Pour Concrete.
Sidewalk Width and Thickness Standards
Sidewalk dimensions are driven by use, not guesswork. Residential walks run 36-48 inches wide; 48 inches lets two people pass comfortably. The ADA sets a 36-inch absolute minimum clear width, with 48 inches preferred, and caps cross-slope (side-to-side tilt) at 2% so the surface stays usable for wheelchairs. Running slope (along the path) should stay at or below 5% to avoid being classified as a ramp.
Thickness is simpler: 4 inches handles all foot traffic, wheelbarrows, and freeze-thaw. Step up to 6 inches only where vehicles cross the walk - driveway aprons and curb cuts - because the 4-inch section will crack under wheel loads.
| Sidewalk Type | Width | Thickness | Key Spec |
|---|---|---|---|
| Garden path | 24-36 in | 3-4 in | Low foot traffic |
| Residential walk | 36-48 in | 4 in | Standard front/side yard |
| ADA compliant | 48-60 in | 4 in | 36 in min, 2% max cross-slope |
| Driveway crossing | 48-72 in | 6 in | Carries vehicle loads |
Cost Per Square Foot vs. Per Linear Foot
Sidewalks are quoted two ways, and the gap between them confuses most homeowners. Installed plain flatwork runs $8-13 per square foot - higher than the $6-12/sq ft baseline for open slabs. The reason is geometry: a 4-foot-wide walk has form work on both long edges for every 4 square feet of surface, so the edge-and-finish labor per square foot is far higher than on a 20x20 patio. Narrower runs cost even more per square foot for the same reason.
Because width is roughly fixed, contractors often quote per linear foot instead. At 4 feet wide and $8-13/sq ft, that is about $32-52 per linear foot of finished walk.
| Width | Cost/Linear Ft (at $8-13/sq ft) |
|---|---|
| 3 ft | $24-39 |
| 4 ft | $32-52 |
| 5 ft | $40-65 |
| 6 ft | $48-78 |
Sidewalk Cost by Length and Size
The table below estimates installed cost for common residential runs at the standard 4-inch thickness. Read the low end as a broom finish in a low-cost region and the high end as decorative or freeze-thaw work in a high-cost metro.
| Sidewalk Size | Square Feet | Installed Cost ($8-13/sq ft) |
|---|---|---|
| 20 ft x 3 ft | 60 | $480-780 |
| 30 ft x 4 ft | 120 | $960-1,560 |
| 40 ft x 4 ft | 160 | $1,280-2,080 |
| 50 ft x 4 ft | 200 | $1,600-2,600 |
| 60 ft x 5 ft | 300 | $2,400-3,900 |
| 100 ft x 4 ft | 400 | $3,200-5,200 |
Add $3-8/sq ft for stamped or colored finishes, and $2-4/sq ft if existing concrete must be demolished first. A 6-inch driveway-crossing section adds roughly $1-2/sq ft over the 4-inch price. For total-project numbers across other flatwork, use the Concrete Cost Calculator.
Concrete Volume and Mix
Volume scales directly with the surface area times thickness. A 30-foot residential walk (4 ft wide, 4 in thick) needs 1.48 cubic yards of concrete - about 67 bags of 80-lb mix before waste, or roughly 74 bags (1.63 cu yd) with 10% waste.
| Length (4 ft wide, 4 in) | Concrete Volume | 80-lb Bags (+10%) |
|---|---|---|
| 20 ft | 0.99 cu yd | 49 |
| 30 ft | 1.48 cu yd | 74 |
| 40 ft | 1.98 cu yd | 98 |
| 60 ft | 2.96 cu yd | 147 |
Specify a 3,500-4,000 PSI mix for exterior walks. In freeze-thaw climates use air-entrained concrete so water can expand without spalling the surface. Bagged mix is practical under about 1 cubic yard (roughly 20 linear feet at standard width); beyond that, ready-mix at $130-170 per cubic yard delivered is cheaper and faster. See the bagged vs. ready-mix comparison to decide.
Control Joints and Reinforcement
Shrinkage cracking is inevitable - control joints give the slab a planned place to crack cleanly. The rule of thumb is to space joints at no more than 2-3 times the slab thickness in inches, which for a 4-inch walk lands around 5 feet. A practical trick: set joint spacing roughly equal to the walk's width, so a 4-foot walk gets joints every 4 feet, forming near-square panels that resist lengthwise cracking.
| Thickness | Max Joint Spacing | Groove/Cut Depth |
|---|---|---|
| 3 in | 5-6 ft | 3/4 in |
| 4 in | 5-8 ft | 1 in |
| 6 in | 8-12 ft | 1.5 in |
Cut joints to one-quarter of the slab depth with a groover during finishing, or saw-cut within 6-18 hours of pouring. Plain residential walks usually do not need rebar; #3 or #4 bar or 6x6 wire mesh is added only at vehicle-crossing sections or over weak subgrade. Place a 1/2-inch foam expansion joint where the walk meets a house wall, steps, or existing concrete.
Base, Slope, and Permits
Compact 4 inches of gravel (3/4-inch crushed stone or road base) under the walk. Slope the finished surface 1/4 inch per foot - about 2% - away from structures for drainage, which also happens to match the ADA cross-slope ceiling.
Most detached residential walks on private property need no permit, but any sidewalk in the public right-of-way (between the curb and your property line) almost always requires a municipal permit and must meet local ADA detailing - permit fees typically run $50-200. Confirm before you pour; see our permit requirements guide.
DIY vs. Hiring a Pro
A short walk is one of the more DIY-friendly concrete projects. Under about 1 cubic yard (roughly a 20-foot run), bagged mix and a couple of helpers can save 50-60% on labor. Beyond that, ready-mix delivery and a finisher are worth it - long walks must be poured and finished within a single set window, and a poor slope or finish on a front walk is highly visible.
Hire a pro when the run exceeds ~30 feet, crosses a driveway, sits in the public right-of-way, or demands a decorative finish. For the full pour sequence, see How to Pour Concrete; to scope a wider paved area, switch to the Concrete Slab Calculator. Enter your walk's length, width, and thickness above to get an exact volume, bag count, and cost estimate in seconds.