Concrete Steps Calculator
Estimate how much concrete you need to pour solid steps with or without a top landing. Get the volume in cubic yards, cubic feet and cubic meters, the number of premixed bags and a step-by-step breakdown.
Don't count the top platform or porch: risers = steps + 1
Typical 6–7.75 in (15–19 cm)
Typical 10–12 in (25–30 cm)
0 if the steps lead up to an existing porch or slab
How to use the Concrete Steps Calculator
- Choose inches or centimeters.
- Enter the number of steps (treads, not counting the top platform) and the stair width.
- Enter the rise and run of each step.
- Enter the platform depth, or 0 if the steps lead up to an existing porch.
- Read the concrete volume and bag count, and check the total rise matches your opening.
Concrete steps formula
For n steps with rise R, run T and width W, plus an optional platform of depth P:
- Steps = T × R × W × n × (n + 1) ÷ 2
- Platform = P × (n + 1) × R × W
- Total = steps + platform, then add 5–10% for waste and uneven ground
Units: in³ ÷ 1,728 = ft³, ft³ ÷ 27 = yd³, cm³ ÷ 1,000,000 = m³. One cubic yard is 0.7646 m³.
Premixed concrete bag yields
| Bag size | Yield per bag | Bags per cubic yard | Bags per m³ |
|---|---|---|---|
| 40 lb (18 kg) | 0.30 cu ft (8.5 L) | 90 | 118 |
| 60 lb (27 kg) | 0.45 cu ft (12.7 L) | 60 | 79 |
| 80 lb (36 kg) | 0.60 cu ft (17 L) | 45 | 59 |
Yields are typical for standard concrete mix; check the bag for the exact figure. A 25 kg bag yields roughly 11–12 liters.
Frequently asked questions
How do you calculate concrete for steps?
Treat each step as a solid block from the ground: step k is k × rise tall. Volume = run × rise × width × (1 + 2 + … + n), plus the platform depth × full height × width. Convert cubic inches to cubic feet by dividing by 1,728, then to cubic yards by dividing by 27.
How much concrete do I need for 3 steps?
Three steps 48 in wide with a 7 in rise, 11 in run and a 36 in landing (28 in high) need about 40.8 cubic feet, or 1.51 cubic yards. With 10% extra that is about 1.66 cubic yards, or 75 bags of 80 lb premix.
How many bags of concrete for steps?
An 80 lb bag of premixed concrete yields about 0.60 cubic feet, a 60 lb bag about 0.45 and a 40 lb bag about 0.30. Divide the cubic feet needed by the bag yield and round up. Above about 1 cubic yard, ready-mix delivery is often easier.
What is a good rise and run for steps?
Comfortable outdoor steps usually have a 6–7 in (15–18 cm) rise and an 11–14 in (28–35 cm) tread. Local building codes set limits, often a maximum rise of 7.75 in and a minimum tread of 10 in for residential stairs.
Can I use less concrete for steps?
Yes. Large steps are often filled with compacted gravel, rubble or blocks inside the forms, leaving a concrete shell of 4–6 in. This calculator gives the solid volume, so your actual pour will be less if you use fill.
Why is the number of risers one more than the steps?
Each tread sits on a riser, and one final riser steps up onto the platform or porch. So 3 treads need 4 risers, and the total height is 4 × rise.