🪜 Concrete Stairs Calculator
Calculate concrete volume and materials needed for concrete stairs
Total vertical height to climb
How to Use This Calculator
Enter Total Rise
Input the total vertical height (rise) in inches from the bottom landing to the top landing. This is the total height the stairs must climb.
Specify Stair Dimensions
Select stair width (standard is 36 inches), tread depth (standard is 11 inches), and riser height (standard is 7.5 inches). These affect comfort and code compliance.
Calculate and Review
Click "Calculate Concrete Stairs" to see number of steps, total concrete volume in cubic yards, bags needed, and total run. Add 10% extra for waste.
Order Materials
Order ready-mix concrete by cubic yards or bagged concrete by bag count. Remember to order forms, rebar, and other materials separately for stair construction.
Formula
Number of Steps = Total Rise ÷ Riser Height
Actual Riser Height = Total Rise ÷ Number of Steps
Total Run = (Number of Steps - 1) × Tread Depth
Stair Volume = (Tread Depth × Riser Height × Width × Steps) ÷ 12³
Volume (cu yd) = Volume (cu ft) ÷ 27
Example 1: Standard Stairs (96" rise, 36" width, 11" tread, 7.5" riser)
Step 1: Calculate steps: 96 ÷ 7.5 = 12.8 → 13 steps
Step 2: Actual riser: 96 ÷ 13 = 7.38 inches
Step 3: Total run: (13 - 1) × 11 = 132 inches (11 feet)
Step 4: Calculate volume: (11/12 × 7.38/12 × 36/12 × 13) = 26.4 cu ft
Step 5: Convert to cubic yards: 26.4 ÷ 27 = 0.98 cu yd
Example 2: Larger Stairs (120" rise, 42" width, 12" tread, 7.5" riser)
Step 1: Calculate steps: 120 ÷ 7.5 = 16 steps
Step 2: Total run: (16 - 1) × 12 = 180 inches (15 feet)
Step 3: Calculate volume: (12/12 × 7.5/12 × 42/12 × 16) = 52.5 cu ft
Step 4: Convert to cubic yards: 52.5 ÷ 27 = 1.94 cu yd
About Concrete Stairs Calculator
The Concrete Stairs Calculator is an essential tool for contractors, builders, and DIY enthusiasts who need to accurately determine the volume of concrete required for concrete stair installations. This calculator eliminates guesswork by providing precise volume calculations based on total rise, stair width, tread depth, and riser height, helping you order the right amount of concrete without waste or shortages.
When to Use This Calculator
- Stair Installation: Calculate concrete volume for new concrete stair installations
- Entry Steps: Determine concrete needed for entry steps and porch stairs
- Basement Stairs: Estimate concrete for basement stair construction
- Budget Planning: Calculate material costs by determining exact concrete volumes needed
- Contractor Estimates: Quick reference for contractors bidding stair projects
Why Use Our Calculator?
- ✅ Accurate Volume Calculation: Precise calculations prevent over-ordering or running short
- ✅ Step Calculation: Automatically calculates number of steps based on rise and riser height
- ✅ Bag Calculations: Shows number of bags needed for both 60 lb and 80 lb bags
- ✅ Cubic Yards: Shows volume in cubic yards for ready-mix concrete ordering
- ✅ Total Run: Calculates total horizontal distance (run) for planning
- ✅ Time Savings: Instant calculations eliminate manual math and measurements
Common Applications
Stair Installation: Contractors and builders installing concrete stairs use this calculator to order the correct volume of concrete. Standard stairs use 7-7.5 inch risers and 11 inch treads, which this calculator helps determine accurately.
Entry Steps: Homeowners and contractors planning entry steps use this tool to estimate concrete quantities needed. Entry steps typically use similar dimensions to interior stairs but may be wider.
Basement Stairs: Builders planning basement stair construction use this calculator to determine concrete volumes needed, ensuring sufficient materials are on-site before starting work.
Tips for Best Results
- Riser Height: Standard is 7-7.5 inches; too high (over 8") is uncomfortable, too low (under 6") wastes steps
- Tread Depth: Standard is 11 inches; minimum is 10 inches; deeper (12-13") is more comfortable
- Add Waste: Always add 10% extra for waste, spills, and mistakes
- Forms: Order forms separately - stairs require complex formwork
- Rebar: Order rebar separately for stair reinforcement
- Code Compliance: Ensure riser height and tread depth meet local building code requirements
Frequently Asked Questions
How much concrete do I need for concrete stairs?
Concrete needed depends on total rise, stair width, and number of steps. For example, stairs with 96-inch rise, 36-inch width, and 13 steps need approximately 0.98 cubic yards of concrete (about 88 bags of 80 lb concrete). Always add 10% extra for waste.
What is the standard riser height for concrete stairs?
Standard riser height is 7-7.5 inches for comfortable climbing. Building codes typically require risers between 4 and 7.75 inches. Riser height over 8 inches is uncomfortable and may violate codes. All risers must be uniform height.
What is the standard tread depth for concrete stairs?
Standard tread depth is 11 inches, with minimum of 10 inches required by most building codes. Deeper treads (12-13 inches) are more comfortable but take more space. All treads must be uniform depth.
Do concrete stairs need rebar?
Yes! Concrete stairs typically require rebar reinforcement for strength and durability. Standard is #4 or #5 rebar placed horizontally in each step and vertically in the risers. Consult building codes or an engineer for specific requirements.
How wide should concrete stairs be?
Standard stair width is 36 inches for residential stairs. Minimum width is 30 inches for residential, 44 inches for commercial. Wider stairs (42-48 inches) are more comfortable but require more concrete. Choose based on use and code requirements.
Can I build concrete stairs without forms?
No! Concrete stairs require forms to create the step shape. Forms can be made from wood, metal, or prefabricated systems. Proper formwork is essential for stairs with correct riser height and tread depth. Hire a professional or follow detailed plans if building yourself.