About the Concrete Steps Calculator
This concrete steps calculator estimates the volume of concrete needed to pour a solid set of stairs, such as front-door, porch or patio steps. Enter the number of steps, the rise (height) and run (tread depth) of each step, the width of the stairs and the depth of any top landing or platform, and it returns cubic feet, cubic yards and the number of premix bags.
It suits DIYers pouring small steps with bagged concrete and anyone ordering ready-mix for a larger stoop. Each step is treated as a solid block from the ground up, stacked like a staircase, which is how most small steps are formed. A top landing is a solid block as tall as all the steps together.
Add 5–10% waste for uneven ground, form bulging and spillage. If you fill the core with compacted gravel or rubble, the concrete needed will be lower than this solid-pour estimate.
With the default inputs, the concrete needed is 2.01 cu yd. Change any value above to recalculate instantly.
How to use the concrete steps calculator
- 1Measure the total height from the ground to the door threshold and divide into equal risers (about 7 in each).
- 2Enter the number of steps, rise and run of each step, and the stair width.
- 3Add the depth of any top landing.
- 4Set waste and choose your bag size or ready-mix price.
- 5Order the cubic yards or bags shown before building the forms.
Formula and method
Solid steps are modelled as a stack of rectangular blocks: the first step is one rise tall, the second two rises tall, and so on, each one tread deep and the full stair width. Adding them gives W × Run × Rise × (1 + 2 + … + n), and the sum 1 + 2 + … + n equals n(n + 1)/2. A top landing is a single block as tall as all the steps (n × Rise) and as deep as the landing.
Working in inches, the volume is divided by 1,728 to get cubic feet and by 27 again for cubic yards. A waste allowance is added, and bag counts use typical premix yields of 0.30, 0.45 and 0.60 cubic feet for 40, 60 and 80 lb bags.
- W
- Stair width (in)
- Run
- Tread depth of each step (in)
- Rise
- Height of each step (in)
- n
- Number of steps
Worked examples
Four 4 ft steps with a 36 in landing
The steps hold 48 × 11 × 7 × 10 = 36,960 in³ and the 28 in tall landing 48 × 36 × 28 = 48,384 in³, a total of 49.39 cu ft. With 10% waste that is 54.33 cu ft, 2.01 cu yd, or 91 × 80 lb bags.
Three 5 ft wide patio steps, no landing
Volume is 60 × 12 × 6.5 × 6 = 28,080 in³, or 16.25 cu ft. Adding 5% gives 17.06 cu ft (0.63 cu yd), which is 38 bags of 60 lb premix at 0.45 cu ft each.
Frequently asked questions
How much concrete do I need for 3 steps?+
For three 4 ft wide steps with a 7 in rise and 11 in run, the solid steps need about 12.8 cu ft of concrete before waste, or roughly 22 × 80 lb bags. A top landing adds considerably more.
What is the standard rise and run for concrete steps?+
US residential codes generally limit risers to 7¾ in and require treads of at least 10 in. Many outdoor steps use about 6–7 in risers and 11–12 in treads for comfortable walking.
How many bags of concrete are in a yard?+
One cubic yard is 27 cubic feet, so it takes about 45 × 80 lb bags, 60 × 60 lb bags or 90 × 40 lb bags to make a yard of concrete.
Can I fill concrete steps with gravel to save concrete?+
Yes. Large steps are often built with a core of compacted gravel or rubble and a concrete shell at least 4 in thick. That reduces concrete but requires careful compaction to avoid settling.
Do concrete steps need rebar?+
Rebar or wire mesh is recommended for most poured steps to control cracking, and steps attached to a foundation are often pinned to it with dowels. Follow local code for frost footings.