Steps calculator
Concrete steps
calculator
A flight of steps is a staircase in cross-section, so the concrete grows with the square of the step count — six steps take three and a half times what three take. Enter your rise and tread and get the volume, the bags and a check against residential stair limits.
Enter measurements ↓Optional
What will it cost?
Enter what you actually pay per cubic yard and the quantities above are priced up. The field starts at a typical US price so you have something to work from — change it to your own.
Typical US range $125–$195 per cubic yard, checked 2026-08-29. Prices move — use your own supplier's figure.
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Put these figures to work
Sizing one part of a pour is easier when the slab itself is settled. Start with the main estimate, then come back for the detail.
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Based on your result
What you'll need
Quantities update after every calculation. Steps eat formwork — every riser needs a board held straight against wet concrete.
- Ready-mix concrete
- Bags for the flight and the landing
- Calculate above
- Riser boards
- One straight board per step, plus side forms
- —
- Rebar or mesh
- Ties the flight together and controls cracking
- —
- Float and edger
- Step trowel, edging tool, stiff broom for grip
- As needed
The maths
How this concrete steps calculator works
Look at a flight from the side and it is a stack of rectangles: the bottom step runs the full depth of the flight, the next is one tread shorter, and so on to the top. Adding those gives rise × tread × N(N+1)/2 — which is why doubling the steps does not double the concrete.
flight = cross-section × width
landing = width × depth × thickness
ordered = (flight + landing) × waste
- 7.75 in
- maximum rise
- 10 in
- minimum tread
- 24–25
- 2 × rise + tread
- 3.5×
- 6 steps vs 3 steps
- 0.60 ft³
- per 80 lb bag
- 27 ft³
- = 1 cubic yard
-
01
Divide the total height first
Measure from finished grade to the landing, then divide by a rise between 6 and 7.75 inches until it comes out whole. Every step in a flight must be the same height.
-
02
Stack the cross-section
Each step sits on everything below it, so the area is rise × tread × N(N+1)/2 rather than a simple multiple.
-
03
Add the landing
The slab at the top is a plain rectangle and is usually thicker than a tread. It is entered separately.
-
04
Check it walks
Twice the rise plus the tread should land between 24 and 25 inches. A flight can meet code and still feel wrong underfoot.
-
05
Pad and convert
Steps lose more concrete than flatwork — it slumps off risers and sticks to forms — so keep the allowance at 10% or above.
Good to know
Concrete stair questions, answered
A three-step flight 4 feet wide with a 7-inch rise and an 11-inch tread takes about 12.8 cubic feet — roughly half a cubic yard, or 22 eighty-pound bags. Add the landing on top of that.
Because each step sits on the ones below it. Three steps give a cross-section of six tread-by-rise rectangles; six steps give twenty-one. That is three and a half times the concrete for twice the steps.
A rise of 6 to 7.75 inches with a tread of 10 to 12 inches suits almost all residential work. The old rule is that twice the rise plus the tread should land between 24 and 25 inches — a 7-inch rise with an 11-inch tread hits 25 exactly.
Steps attached to a house usually sit on a footing below the frost line, or they will heave and pull away from the wall. Free-standing steps on stable ground often sit on compacted gravel. Local code decides.
For a wide flight, yes — a compacted fill core with a 4 to 6 inch concrete shell over it is common and saves a lot of material. This calculator sizes a solid pour, so treat its figure as the upper bound.
Yes for anything more than a couple of steps. Rebar or mesh through the flight and dowels into the footing keep the nose of each tread from breaking off and stop the flight cracking away from the structure.
Forms usually come off after 24 to 48 hours, and light foot traffic is fine at about three days. Full strength takes 28 days, so keep heavy loads and any edge impact off until then.