Concrete Steps Cost Calculator
Estimate concrete quantity and cost for a set of outdoor concrete steps.
Concrete needed
0.39 yd³
for 3 steps, 36 in wide
- Cubic feet
- 10.6 ft³
- Cubic yards
- 0.39 yd³
- Bags needed
- 18 bags
Short answer
A common 3-step staircase, 36 inches wide with an 11-inch tread and 7-inch riser, needs about 0.39 cubic yards of concrete — roughly 18 bags of 80 lb premix, plus whatever the local ready-mix or bag price runs. More steps or a wider staircase scale the volume, and therefore the cost, up quickly.
Standard riser and tread dimensions
| Measurement | Comfortable range | Notes |
|---|---|---|
| Riser height | 6–8 in | 7 in is a common, comfortable default |
| Tread depth (run) | 11–12 in | Deeper treads feel more comfortable outdoors |
| Staircase width | 36 in or your door/walkway width | Match to the opening the steps serve |
How concrete steps are calculated
- Measure the total rise (height) you need to climb and divide by a comfortable riser height (6–8 inches) to get the number of steps.
- Pick a tread depth — 11 inches is a common, comfortable default for outdoor steps.
- Enter the number of steps, width, tread depth, and riser height above to get the concrete volume and bag count.
- The calculator treats each step as a stacked rectangular slab, so the bottom step carries the full stack height and the top step only its own riser — this models the solid stair shape reasonably well for estimating purposes.
- Form the stringers (side walls) first, then pour from the bottom step up, consolidating each level before moving to the next.
- Broom-finish each tread for traction, and consider a nosing edge for a finished look.
Worked example
- Inputs
- 3 steps, 36 in wide, 11 in tread, 7 in riser
- Volume
- width × tread × riser × (n×(n+1)/2) = 36 × 11 × 7 × 6 = 16,632 in³ = 9.63 ft³, plus 10% waste = 10.59 ft³
- Bags (80 lb, 0.60 ft³ each)
- ceil(10.59 / 0.60) = 18 bags
Common mistakes
- Using inconsistent riser heights between steps, which is a common tripping hazard and often a code violation.
- Underestimating volume by treating steps as a simple ramp instead of stacked, full-depth treads.
- Skipping stringer forms on the sides, which lets wet concrete bulge or leak out during the pour.
- Not broom-finishing the treads, leaving a smooth, slippery surface in wet or icy conditions.
Assumptions
- Volume is calculated as stacked full-width, full-depth rectangular slabs, which is a common simplified estimate for stair concrete.
- Standard premix concrete at roughly 150 lb per cubic foot.
- Bag yields follow manufacturer averages: 80 lb = 0.60 ft³, 60 lb = 0.45 ft³, 50 lb = 0.375 ft³, 40 lb = 0.30 ft³.
- Does not include stringer forms, rebar, footings under the steps, or finish materials.
Frequently asked questions
What are standard riser and tread dimensions for steps?
6 to 8 inches for riser height and 11 to 12 inches for tread depth are comfortable, commonly used dimensions for outdoor concrete steps. Consistency between steps matters more than the exact numbers.
Do concrete steps need rebar?
Most poured concrete steps benefit from rebar or wire mesh to resist cracking, especially where steps sit on a footing rather than solid ground. Larger or freestanding staircases should be reinforced.
How do you calculate concrete for stairs?
A simple and common method treats each step as a stacked rectangular slab: multiply the staircase width by the tread depth and riser height, then multiply by the sum of 1 through the number of steps to account for the stacked shape.