Stairs Concrete Calculator
Accurately calculate concrete volume for stairs. Get bag counts (60lb, 80lb) and waste estimates for your construction project.
Stairs
Volume
- Cubic yards:0.46
- Cubic meters:0.35
- Cubic feet:12.47
Bags (approx.)
- 60-lb bags:27.71
- 80-lb bags:20.78
Assumes ~0.45 ft³ per 60-lb bag and ~0.60 ft³ per 80-lb bag. Add 5–10% waste.
Tips
- Add 5–10% extra for waste and uneven ground.
- Confirm local building codes for thickness and reinforcement.
- Choose 60lb or 80lb bags based on handling preference.
Stair Calculator Notes
- Volume is estimated as a triangular stair section plus a rectangular landing, multiplied by stair width.
- Common residential dimensions are around 7 in rise × 11 in run, but always follow local building codes.
- Chamfers, nosing, and rounded edges reduce volume slightly—add extra concrete for waste allowance.
- Consider reinforcement and proper footing under stairs to prevent settlement or cracking.
Stairs FAQ
Q1How do I calculate concrete volume for stairs?›
Concrete stairs are modeled as a right triangle plus platform area × width. The stairs calculator handles this geometry for you.
Q2What is the standard rise and run for concrete steps?›
Common residential stairs use a 7-inch rise and 11-inch run per step, but this varies by code and comfort.
Q3Do concrete stairs require rebar?›
Yes, most concrete stairs need rebar reinforcement to prevent cracking. The calculator gives volume; reinforcement should follow building code.
Q4How many bags of concrete do I need for 5 steps?›
It depends on the width and platform depth. For example, 5 steps at 3 feet wide may require ~0.8 cubic yards (~36 bags of 60lb).
Q5Should I order extra concrete for stairs?›
Yes, add 5–10% extra for uneven formwork and finishing. The stairs calculator includes this waste allowance.