Concrete steps calculator

Three solid steps 4 ft wide, with a 7 in rise and an 11 in tread, take 12.83 cu ft (0.48 cubic yards) of concrete. With 10% extra that is 24 bags of 80 lb mix.

Number of steps

Width of the steps

Rise (height of each step)

Run (depth of each tread)

Top landing depth (0 if none)

Extra for waste

0.52 cubic yards

24 80 lb bags

32 60 lb bags

Volume	12.83 cu ft (0.48 cu yd, 0.363 m³)
With 10% extra	14.12 cu ft (0.52 cu yd)
Ready-mix to order	0.75 cu yd (rounded up to the next ¼ yard)
40 lb bags	48 (0.3 cu ft each)
50 lb bags	38 (0.375 cu ft each)
60 lb bags	32 (0.45 cu ft each)
80 lb bags	24 (0.6 cu ft each)
90 lb bags	21 (0.675 cu ft each)
Weight of the concrete	about 2,047 lb (1.02 tons)

How it was worked out

Steps: 4 ft wide × 11 in tread × 7 in rise × (1 + 2 + … + 3) = 12.83 cu ft

12.83 cu ft ÷ 27 = 0.48 cu yd

How the volume is worked out

The calculator treats the steps as solid concrete from the ground up. Seen from the side, the bottom step is a block one rise tall, the second step two rises tall, and so on to the top. Each block is as wide as the steps and as deep as one tread, so the total is width × tread × rise × (1 + 2 + … + the number of steps).

Steps: 4 ft wide × 11 in tread × 7 in rise × (1 + 2 + … + 3) = 12.83 cu ft

12.83 cu ft ÷ 27 = 0.48 cu yd

If the top step opens onto a landing, enter the landing's depth from front to back. It is poured at the full height of the stairs, so it often holds more concrete than the steps. Three steps like the ones above with a 36 in landing need 1.38 cubic yards with 10% extra.

Steps poured over fill

Many builders fill the inside of the forms with compacted gravel or rubble and pour only a shell of concrete over it. That uses far less concrete than a solid pour, and this calculator will overstate it. For that kind of build, work out the shell as slabs and walls, or ask your contractor for the shell thickness.

Concrete for 4 ft wide steps

7 in rise, 11 in tread, solid, no landing
Steps	Cu ft	Cu yd	80 lb bags (with 10%)	60 lb bags (with 10%)
1	2.14	0.08	4	6
2	6.42	0.24	12	16
3	12.83	0.48	24	32
4	21.39	0.79	40	53
5	32.08	1.19	59	79
6	44.92	1.66	83	110

Before you build, check your local code for the largest rise and the smallest tread it allows, and keep every step the same height. Bag counts use the QUIKRETE Concrete Mix yields of 0.60 cu ft per 80 lb bag and 0.45 cu ft per 60 lb bag.

Sources

QUIKRETE Concrete Mix (No. 1101) data sheet, The QUIKRETE Companies, revised October 2022. Bag yields: 40 lb 0.30 cu ft, 50 lb 0.375, 60 lb 0.45, 80 lb 0.60, 90 lb 0.675; about 140 lb per cubic foot.
CIP 8: Discrepancies in Yield (Concrete in Practice series), National Ready Mixed Concrete Association, 2016 edition. Order at least 4 to 10 percent more than the measured volume; 1/8 in extra on a 4 in slab is a 3 percent shortfall.