Concrete calculator

Concrete stairs

Triangular-step volume, ready-mix order and bag equivalent from riser, tread, width and count.

Reviewed formula · v1.0.0

Project inputs

Enter field measurements. Imperial lengths take feet and inches. Unit conversion happens before the reviewed formula is applied.

RiserscountNumber of risers in the runRiser heightinFinished riser heightTread depthinFinished tread run, nosing excludedStair widthft + inFinished width of the stairftinWaste factor%Allowance for over-excavation, forms and spill

All values can be refined when you edit the estimate. This tool does not replace field verification or local requirements.

Calculated result

0.5yd³

Ready-mix order

FormulaCONC-STR-001

V ≈ risers × width × tread × riser ÷ 2 × (1 + waste) → ready-mix order

9.36 ft³

Net volume

0.35 yd³

Net volume

Bag table · waste in

Counts round up. A cubic yard is 45 of 80 lb, 60 of 60 lb, 72 of 50 lb, 90 of 40 lb.

Bag	Count
40 lb	35
50 lb	28
60 lb	23
80 lb	18

Transparent cost view

Planning rates only. Pick a currency — badges, inputs, and totals follow. Material is a rate. Labour is hours × a planning hourly rate. Equipment and delivery are this-job amounts.

Material ratePlanning · per calculated unit · USDEquipmentPlanning · this job · USDDeliveryPlanning · this job · USDLabour hoursPlanning · this jobLabour ratePlanning · per hour · USDOverhead %%Contingency %%Markup %%Tax %%

Planning defaults are office figures, not a bid. US ready-mix in 2026 often lands around $125–165 per cubic yard delivered; place-and-finish commonly $2–4 per square foot. Replace every rate with a supplier or crew quote before you send the letter.

Indicative FX as of Aug 2026. Planning conversion, not a live bank rate.

Material costUSD 42.50

Labour (8 h)USD 280

Direct costUSD 433

Overhead + contingencyUSD 43.25

Markup + taxUSD 57.09

Estimated project totalUSD 533

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Embed this calculator

<iframe src="https://construclytic.com/embed/concrete-stairs" title="Concrete stairs" width="100%" height="820" loading="lazy" referrerpolicy="strict-origin-when-cross-origin" style="border:1px solid #d7e0da;border-radius:16px;background:#fff;"></iframe>

Paste on a contractor site or blog. The iframe is a planning takeoff, not a bid.

How this calculator works

A transparent concrete stairs takeoff.

This calculator treats each stair as a right-triangle prism, then applies a visible waste allowance before ready-mix rounding.

Worked example. Example: 10 risers, 7 in high and 11 in deep, 3.5 ft wide, contain about 9.36 ft³. With 10% waste the ready-mix order rounds to 0.5 yd³.

1. Count risers on the finished run, not treads.
2. Enter the specified riser and tread, not a code guess.
3. Add landings and closed risers as separate lines.

Need the broader workflow? Read the concrete planning guide.

Questions

Questions about concrete stairs

Does this size the stair?

No. Rise, run, headroom, reinforcement and local code stay with the responsible professional.

Open or closed risers?

The volume is a triangular prism. Closed risers, waists and landings need extra concrete — add them as their own takeoff.

What is the formula ID?

This calculator publishes formula CONC-STR-001, version 1.0.0. The ID stays on the result and on the estimate line.

Is this engineering advice?

No. Construclytic is a planning website, not a registered engineering or contracting firm. Field checks, codes and product data still sit with you.

Does Construclytic fetch live supplier prices?

No. Costs use the rate you enter. Construclytic does not fetch live supplier prices.