Concrete Steps Calculator
Calculate concrete volume and bags for a straight flight of solid steps.
Last reviewed September 19, 2026
Result
Buy 24 bags (80 lb)Estimate
Forms flex, sub-bases vary and some concrete stays in the mixer, so the headline includes 10% extra by default.
- Concrete, allowance included
- 0.5228 yd³ (14.1167 ft³)
- Minimum if everything goes perfectly
- 12.8333 ft³ (0.4753 yd³)
- Total rise
- 1.75 ft (21 in)
- Total run
- 2.75 ft (33 in)
https://calcgallery.com/concrete/concrete-steps-calculator/
Results are estimates for planning only. Actual needs vary with site conditions, products and workmanship. Always confirm quantities with your supplier and follow local building codes and manufacturer instructions. Read the full disclaimer
How to use it
- Enter the clear width of the steps.
- Enter one tread depth and one riser height.
- Set the number of equal solid steps.
- Read the concrete volume and bag count.
How it is calculated
The first step is one tread-by-riser layer, the second is two layers, and so on. The layer count is the triangular number n × (n + 1) ÷ 2:
Volume = width × tread × riser × steps × (steps + 1) ÷ 2The calculation assumes a straight flight of equal rectangular steps, solid all the way through. A landing is a separate slab.
Practical limits
Work from finished levels. Surface finishes at the top and bottom alter the first and last riser. Resolve those levels before making forms.
Brace every riser form. Wet concrete pushes outward and a small movement changes both the appearance and the volume.
Do not infer reinforcement from volume. The amount of concrete says nothing about steel, foundations or attachment to an existing structure. Follow the project design and local requirements.
With your numbers
- The 3 step layers total 6 tread-by-riser prisms
- Solid volume = 12.83 ft³
- With 10% extra = 14.12 ft³
- Rounded up to 24 bags
Quick reference
Forms flex, sub-bases vary and some concrete stays in the mixer, so the headline includes 10% extra by default.
| Job | Bags to buy |
|---|---|
| 3 steps, 4 ft wide | 24 |
| 4 steps, 4 ft wide | 40 |
| 5 steps, 5 ft wide | 74 |
| 2 steps, 6 ft wide | 20 |
| 3 steps, 1.2 m wide | 42 |
| 5 steps, 1.5 m wide | 130 |
Common questions
- How much concrete do three 4 ft wide steps need?
- At an 11 in tread and 7 in riser, the solid volume is 12.83 ft³. With 10% extra, that is about 14.12 ft³ or 24 bags of 80 lb premix.
- Does this include a landing?
- No. Add a landing separately with the concrete slab calculator. This page models only equal solid steps.
- Can I use this for hollow steps or steps over compacted fill?
- Not directly. The formula assumes every layer is solid concrete, so it will overstate concrete where a documented void or fill volume replaces it.
- Does the result mean the steps meet code?
- No. Rise, tread, landings, handrails, reinforcement and foundations are regulated differently by location. Check the design before forming or pouring.