Concrete Steps Calculator
Four standard concrete steps (48 in wide, 7-in rise, 12-in tread) take about 0.8 cubic yards of concrete — roughly 36 bags of 80-lb mix. Enter your step count and dimensions below to get exact volume and bag count for any stair flight.
Pro Tips
- →Standard step rise is 7-7.5 inches
- →Step tread depth should be 11-12 inches minimum
- →Include rebar reinforcement in steps
- →Add non-slip finish for safety
- →Build steps slightly wider than doorway or path
Includes 10% waste factor
That's typically a professional pour. See costs ↓
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Cost Estimate
Estimated material costs for your project
Recommendation: Bagged Concrete
For smaller projects, bagged concrete gives you more control and less waste.
18 bags × 80lb
0.39 cubic yards + delivery
Prices vary by location and time. Contact local suppliers for accurate quotes.
For general step-by-step instructions, read our complete When To Use Rebar and How To Pour Concrete.
What This Calculator Covers
Concrete volume for poured-in-place stair flights from 2 to 8 steps, at any width. The geometry is the part homeowners get wrong: each successive step sits on top of the one below, so a flight of stairs is essentially a triangular wedge of concrete — not a stack of thin slabs. A typical 4-step flight at 48 inches wide takes about 0.8 cubic yards (36 bags of 80-lb mix), which is more than most people expect.
For the cost side of the same project (materials plus labor for a contractor pour), use the concrete steps cost calculator.
Step Volume by Count
The table below assumes 48-inch-wide steps with a 7-inch rise and 12-inch tread — the most common residential dimensions. Wider or narrower steps scale linearly with width.
| Number of Steps | Total Rise | Volume (cu yd) | 80-lb Bags (incl. 10% waste) |
|---|---|---|---|
| 2 steps | 14 in | 0.30 | 14 |
| 3 steps | 21 in | 0.55 | 26 |
| 4 steps | 28 in | 0.80 | 36 |
| 5 steps | 35 in | 1.20 | 53 |
| 6 steps | 42 in | 1.65 | 73 |
| 7 steps | 49 in | 2.20 | — (use ready-mix) |
| 8 steps | 56 in | 2.85 | — (use ready-mix) |
Volumes scale by width. For 36-inch (3-ft) steps, multiply by 0.75; for 60-inch (5-ft) steps, multiply by 1.25.
Standard Rise, Tread, and Width
- Rise — 7 to 7.5 inches per step. Building codes (IRC R311.7.5) cap maximum rise at 7.75 inches and require all risers in a flight to be within 3/8 inch of each other. Inconsistent rise heights are the most common code-violation finding on DIY stair pours.
- Tread depth — 11 inches minimum, 12 inches standard. Deeper treads (13–14 in) feel more comfortable on entry stairs and let you skip a step on a quick exit.
- Width — 36 inches minimum for code; 48 inches standard for main entries; 60 inches for grand entries or wherever two people pass.
- Nosing — a 1-inch overhang on each tread improves the visual line and adds a small amount of effective tread depth.
Rebar and Tie-In to Existing Slab
Concrete steps need reinforcement because each tread cantilevers off the supporting mass below. Use #4 (1/2-inch) rebar:
- One horizontal bar near the top of each tread, running the full width
- Vertical bars every 12 inches connecting the layers
- Two longitudinal bars running the full length of the flight, mid-depth
When pouring against an existing slab or porch, drill 5/8-inch holes 4 inches deep into the existing concrete and epoxy in #4 rebar dowels every 12 inches before pouring the new steps. Skip this and freeze-thaw cycling will pull the new flight away from the existing structure within a few winters.
Always install 1/2-inch expansion joint material between the steps and any existing concrete to allow independent thermal movement.
Bagged vs. Ready-Mix for Steps
The practical breakpoint sits at about 1 cubic yard (roughly a 4-step flight at 48 inches wide):
- Under 1 cu yd (2–4 steps) — bagged concrete from a rented mixer is workable. Plan for 2–3 batches mixed back-to-back so the form is filled before any layer starts to set.
- Over 1 cu yd (5+ steps or wider flights) — ready-mix delivery is faster and gives a more consistent set across the whole pour. Expect a short-load fee on anything under 3 cubic yards.
Whichever you choose, finish all steps in a single continuous pour. Stopping mid-flight creates a cold joint that becomes a horizontal crack within a year or two.