Concrete for steps 4 ft wide
| Steps | cu ft | yd³ | 80 lb bags |
|---|---|---|---|
| 2 | 20.4 | 0.76 | 35 |
| 3 | 33.8 | 1.25 | 57 |
| 4 | 49.4 | 1.83 | 83 |
| 5 | 67.1 | 2.48 | 112 |
| 6 | 86.9 | 3.22 | 145 |
How the steps calculation works
Solid steps are a stack of blocks. The first step is one rise high, the second two rises high, and so on. The platform at the top is as tall as all the steps together.
If you fill the inside with gravel or rubble to save concrete, subtract that volume. Many builders do this for wide stairs.
Comfortable step sizes
Most building codes allow a rise of up to about 7¾ in and ask for a run of at least 10 in. Steps around 7 in high and 11 in deep feel natural. Keep every rise the same height, since even a small difference can trip people.
Common questions
How much concrete do I need for 3 steps?
For 3 steps 4 ft wide with a 7 in rise, 11 in run and a 36 in top platform, about 33.8 cubic feet, or 57 bags of 80 lb.
How thick should concrete steps be?
Solid steps are filled all the way through. If you use a fill such as gravel inside, keep at least 4 in of concrete on every face.
Do concrete steps need rebar?
Rebar is common in steps to tie them to the foundation and stop cracks spreading. Check your local code, especially for steps attached to a house.