Concrete Step Calculator
Calculate the exact yardage and bag counts needed to pour solid concrete stairs and landings.
Stair Dimensions
Concrete Required
For estimation purposes only. Verify structural calculations with a licensed engineer.
Concrete Stairs Calculator
Pouring a set of stairs is one of the most challenging DIY concrete projects you can undertake. Unlike a simple flat patio, stairs require complex formwork and a highly accurate concrete step calculator to ensure you have enough material.
When a set of stairs is poured, it is poured monolithically (all at once). If you run out of concrete while pouring the bottom step, the entire structure is ruined. Using our stair calculator for concrete guarantees you order the precise volume needed to complete the job in one continuous pour.
How to Calculate Concrete for Steps
Understanding how to calculate concrete for stairs manually requires breaking the stair assembly down into a series of rectangular blocks.
The most common mistake people make is only calculating the volume of the visible stair treads. However, when you pour solid concrete steps, the concrete fills the space all the way down to the ground. This means the top step requires significantly more concrete than the bottom step.
The Math Behind the Tool:
Step 1 Volume = Width Tread Depth Riser Height
Step 2 Volume = Width Tread Depth (Riser Height 2)
Step 3 Volume = Width Tread Depth (Riser Height 3)
...Sum all steps to get total cubic inches, then convert to cubic yards.
Because this geometry gets extremely tediousespecially when adding a larger top landing into the mixour cement stairs calculator instantly runs the geometric summations for you in the background.
How Many Bags of Concrete for Steps?
Most residential stair replacements consist of 2 to 4 steps leading up to a doorway. For projects this small, it is usually cheaper to buy bags of concrete rather than paying a minimum-load delivery fee for a ready-mix truck.
If you want to know how many bags of concrete for steps you need, our calculator provides instant bag counts for 80lb, 60lb, and 40lb mixes.
- 2-Step Assembly (36" wide): Requires roughly 0.15 cubic yards (7 bags of 80lb concrete).
- 3-Step Assembly (36" wide): Requires roughly 0.32 cubic yards (15 bags of 80lb concrete).
- 4-Step Assembly (48" wide): Requires roughly 0.70 cubic yards (32 bags of 80lb concrete).
Pro Tip: To save money on concrete and reduce the total weight of the structure, contractors often fill the hollow void beneath large stair assemblies with compacted gravel or rubble before pouring the concrete cap over it.