Concrete Steps Calculator

How to measure for concrete steps

Start with the total height, from the ground where the bottom step will land up to the door threshold or the landing. Ground rarely sits level, so measure with a straight board and a level from the threshold. Divide by a riser of up to 7-3/4 inches and round up, and that gives you the number of risers. Divide the height by that number for the exact riser.

Then count properly, because this is where steps go wrong. Count risers. On a run of 3 risers with a landing at the top, you walk on 2 treads and the landing. A sum that adds three treads and then a landing counts one of them twice, which adds concrete you do not need.

3 risers of 7.5 in with 11 in treads, solid, and a 36 in landing: 0.82 cubic yards.

Width and the landing come next. The 2021 IRC asks for 36 inches of clear width and a 36 inch landing at an exterior door. Measure what is really there if you are replacing old steps, because the frame or a storm door can change it. Solid-filled steps are simple, but heavy. A sloped slab with a hollow beneath uses less concrete but needs more careful forms.

A worked example

Here is a flight of 3 risers at 7.5 inches, with 11 inch treads, 36 inches wide, and a 36 inch landing, poured solid. These lines come from the same formula the calculator above runs.

3 risers, solid, with a 36 in landing

Volume: 22.03 cu ft
Cubic yards: 22.03 ÷ 27 = 0.82 cu yd
80 lb bags, at 0.60 cu ft each: 37
Total rise: 22.5 in

Thirty-seven bags is nearly a ton and a half to mix by hand, so this is where a small truckload starts to make sense. The landing is most of the volume here, because it is the full height all the way across. For footing and any slab, use the concrete calculator, and for an indoor flight in wood, the stair calculator.

Concrete for common steps

These use 7.5 inch risers, 11 inch treads, 36 inch width and a 36 inch landing, all poured solid. Look how fast the volume climbs as the flight gets taller, because everything below the top step gets taller as well.

Worked out by this calculator.
Steps	Solid	80 lb bags
1 riser	0.21 cu yd	10
2 risers	0.48 cu yd	22
3 risers	0.82 cu yd	37
4 risers	1.22 cu yd	55
5 risers	1.68 cu yd	76
6 risers	2.20 cu yd	100

Mistakes that make bad steps

Double counting a tread. Count risers, and let the top one rise to the landing.
Uneven risers. The code limits how much they can vary within a flight, and your foot notices a difference long before your eye does.
A landing too shallow. R311.3 asks for 36 inches at an exterior door. A door that swings out can make that feel short.
Ignoring the ground. Footings and frost are not in this calculator, and steps that heave can pull away from the door.
Forgetting the handrail. Four or more risers need one under R311.7.8, and it is easier to plan before you pour.

Questions

How much concrete for 3 steps?

About 0.82 cubic yards for 3 risers at 7.5 inches, with 11 inch treads, a 36 inch landing and a width of 36 inches, poured solid. That is 37 bags of 80 pound concrete. At that amount, price a small delivery as well.

How much concrete for 2 steps?

About 0.48 cubic yards for 2 risers at 7.5 inches, an 11 inch tread, a 36 inch landing, and 36 inches wide, poured solid. That is 22 bags of 80 pound concrete. Count your risers, not your treads, or you can double count one.

What rise and run for outdoor steps?

A riser of no more than 7-3/4 inches and a tread of at least 10 inches, under the 2021 IRC, and Fine Homebuilding reports that the 2024 edition keeps them. Some outdoor designs use lower risers and deeper treads for comfort. Your local code decides.

Do concrete steps need a handrail?

Yes at 4 or more risers, under R311.7.8 of the 2021 IRC. A guard is also required where a walking surface is more than 30 inches above grade, by R312.1.1. Check your local amendments, because towns do change these.

How big should the landing be?

At least 36 inches in the direction of travel at an exterior door, under R311.3. There must be a landing or floor at the top and bottom of each stairway, too. A door that swings out over the landing may need more room in practice.

When do I need a professional?

You need a permit or a pro for steps attached to the house, anything over a few risers, or on frost-prone ground, since footings and reinforcement matter. Steps can settle and pull away from the door. Ask your building department.

These concrete steps sums are a guide using 2021 IRC section R311.7, and they are advisory, so your town's adopted code and inspector decide. Footings, frost depth and rebar are not covered. Solid steps are very heavy, and a poorly built flight can crack, settle or trip someone, so ask about reinforcement before you pour.

Sources and review

2021 residential code, chapter 3, as adopted in Colorado, UpCodes, 2021.
Concrete Mix 1101 data sheet, Quikrete, 2020.
Stairway basics, Fine Homebuilding, 2024.

Checked in November 2026. Spotted a wrong number? Report it and it goes in the corrections log.

How this is calculated

Every figure below is read from the code that produces the answer, so what is written here is what the calculator ran. The constants were last checked against their sources in November 2026.

The arithmetic

Solid steps

Volume = Width × (Run × Rise × (1 + 2 + … to one less than the risers) + Landing × Risers × Rise)

Risers: The top one rises to the landing
Landing: Depth of the top landing

Worked through: 3 risers, 7.5 in rise, 11 in run, 36 in landing and width comes to 22.03 cu ft

Cubic yards

Cubic yards = Cubic feet ÷ 27

27: Cubic feet in a cubic yard

Worked through: 54 ÷ 27 = 2 cu yd

The constants, and where they come from

BAG_YIELD_CU_FT

Published figure

Cubic feet from one bag, by its weight

40: 0.3
60: 0.45
80: 0.6

Applies to: Quikrete Concrete Mix

Source: Concrete Mix 1101 data sheet, Quikrete, published 2020-11, read 2026-11. This source is about 6 years old, and it is the one the figure rests on.

Quikrete's data sheet prints 0.30, 0.45 and 0.60 cubic feet. Check the bag you buy.

MAX_RISER_INCHES

Published figure

Highest riser allowed, in inches

7.75