Concrete steps calculator
Enter how many steps, how wide, and the rise and run of each step to see the concrete for a solid set of poured steps.
Enter your measurements
More options: Extra
- Or ready-mix to order
- 1.38 cu yd (37.2 cu ft)
- Concrete before the extra
- 1.25 cu yd (33.8 cu ft)
- Total height
- 21 in
- Total depth (front of bottom step to back of top)
- 69 in
- Weight of the concrete (≈ 145 lb/cu ft)
- 4,906 lb (2 tons)
Step blocks: 4 ft × 11 in × 7 in × (1 + 2 + … + 3 = 6) + landing 36 in deep × 3 risers tall
= 33.8 cu ft = 1.25 cu yd
+ 10% = 1.38 cu yd ÷ 0.6 cu ft per 80 lb bag = 63 bags
- Total to buy counts this as ready-mix. Switch “How will you buy it?” to bags if you are mixing it yourself.
- Steps attached to a house or porch may need footings below the frost line. Your building department will say.
Quick answers for common sizes
| Example | Answer |
|---|---|
| How much concrete for 3 steps | 63 bags of 80 lb with a 3 ft landing (24 for the steps alone) |
Your steps with more or fewer risers
| Number of steps (risers) | Bags of mix | Or ready-mix to order | Total height |
|---|---|---|---|
| 1 | 17 bags | 0.37 cu yd | 7 in |
| 2 | 38 bags | 0.83 cu yd | 14 in |
| 3 | 63 bags | 1.38 cu yd | 21 in |
| 4 | 91 bags | 2.01 cu yd | 28 in |
| 5 | 123 bags | 2.73 cu yd | 35 in |
| 6 | 160 bags | 3.54 cu yd | 42 in |
Solid concrete steps are a stack of blocks: the bottom step runs the full depth of the stair, the next sits on top of it one tread shorter, and so on. Add the blocks up and you get the volume — which grows quickly, because each new step makes every step below it taller.
How the steps calculation works
volume = width × run × rise × (1 + 2 + … + n) 1 + 2 + … + n = n × (n + 1) ÷ 2 landing = width × landing depth × rise × n
Three steps at 7 in rise and 11 in run, 4 ft wide, is 4 × (11 ÷ 12) × (7 ÷ 12) × 6 = 12.8 cu ft — just under half a yard. Four steps is 21.4 cu ft; five is 32. A deep top landing often uses more concrete than the steps below it, since it is the full height of the stair.
| Steps (7 in rise, 11 in run, 4 ft wide) | Cu ft | 80 lb bags (+10%) | Cu yd (+10%) |
|---|---|---|---|
| 1 | 2.1 | 4 | 0.09 |
| 2 | 6.4 | 12 | 0.26 |
| 3 | 12.8 | 24 | 0.52 |
| 4 | 21.4 | 40 | 0.87 |
| 5 | 32.1 | 59 | 1.31 |
Worked example
Three steps is the size people search for most; it is worked through on how much concrete for 3 steps, with a landing at the door — normally required by code (IRC R311.3 and its local versions) — and 2 and 4 steps as variants.
Before you form the steps
- Check riser and tread sizes with your local code before building forms; stairs that change height from step to step are a trip hazard and may fail inspection.
- Slope each tread slightly (often around ⅛ in per foot) so water runs off rather than freezing on the step.
- Brace the riser boards well — wet concrete pushes hard on them — and bevel the bottom edge of each riser board so you can float the tread right up to it.
- Fill from the bottom step up, and let the concrete stiffen slightly before finishing the upper treads so it doesn’t ooze out under the riser forms.
What you’ll need
- Concrete edger and groover setBudget price
The edger rounds slab edges so they don’t chip; the groover cuts control joints while the concrete is still soft.
See options on Amazon (opens in a new tab) - Magnesium hand floatBudget price
Closes the surface and pushes stones down after screeding, and prepares the slab for a broom or trowel finish.
See options on Amazon (opens in a new tab) - Portable electric concrete mixerPremium price
A small drum mixer turns a long day of hand-mixing into batches of two or three 80 lb bags. Check the drum size against the bag count you need.
See options on Amazon (opens in a new tab) - Steel form stakesMid-range price
Round steel stakes with nail holes hold slab and curb forms in line. Easier to drive and pull than wooden ones.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How many bags of concrete for 4 steps?
Four steps 4 ft wide with a 7 in rise and 11 in run take about 21.4 cu ft, or 40 bags of 80 lb with 10% extra. A top landing adds a lot more.
Can I pour concrete steps over gravel fill to save concrete?
Large steps are often formed around a core of compacted gravel or rubble, with a few inches of concrete on top and at the faces. Follow your plans for how much concrete must surround the fill, and subtract the fill volume from the calculator’s total.
How thick should concrete steps be?
Solid steps are as thick as they are tall. For hollow or filled steps, the concrete thickness over the fill comes from your plans or local practice; the calculator counts solid steps.
How long before I can walk on new concrete steps?
Once the concrete has hardened, light foot traffic is possible, but keep the steps damp and protected while they cure. See the concrete cure time calculator.
Sources
- Quikrete Concrete Mix (No. 1101) data sheet (opens in a new tab) — Yields: 40 lb ≈ 0.30, 50 lb ≈ 0.375, 60 lb ≈ 0.45, 80 lb ≈ 0.60, 90 lb ≈ 0.675 cu ft; unit weight ≈ 140 lb/cu ft; for pours 2 in thick or more; 6–9 pints of water per 80 lb bag; control joints every 6–8 ft; cure 5 days at 70 °F or above, 7 days at 50–70 °F; protect from freezing for 48 hours.
- NIST Handbook 44, Appendix C — General Tables of Units of Measurement (opens in a new tab) — 1 cubic yard = 27 cubic feet; 1 cubic foot = 1,728 cubic inches.