Concrete Steps Calculator
Find how many bags or yards of concrete your steps need.
Measure your project
Your answer
That is 30.2 cubic feet, or 1.12 cubic yards. We added 10% extra.
It weighs about 3,838 lb (1.9 tons) when set. At 140 lb per cubic foot (Quikrete).
If you buy bags
One 80 lb bag makes 0.6 cubic feet of concrete.
If you order a truck (ready-mix)
Ask for 1.25 cubic yards. We round up to the next quarter yard.
This answer is a guide. Steps to a house must meet local rules. Check your local building rules or ask a builder or engineer.
Which costs less?
But you must mix 51 bags by hand. That is 2.0 tons. For a big job, a truck saves a lot of hard work.
Prices are US middle prices from October 2026. Ask your store for their price.
Quick answers
- 3 steps, 4 ft wide, with a 36 in landing
- 51 bags of 80 lb, with 10% extra. That is 1.12 cubic yards.
- What they weigh
- About 3,838 lb once set, at 140 lb per cubic foot.
- Tallest step (IRC)
- For steps to a house, porch or deck: 7¾ in. Each tread must be at least 10 in deep.
- How wide?
- For steps to a house, porch or deck, at least 36 in (IRC). Quikrete says steps for homes are usually 48 in wide.
- What strength?
- 2,500–3,500 psi by weather, says the IRC. The Virginia ready-mix group says ACI 332 asks 4,500 psi where it freezes and thaws.
How to work it out
- Measure how wide the steps will be, in feet.
- Measure the rise (height) and run (depth) of one step, in inches.
- Count the steps. Then measure how deep the top step or landing is.
- Picture each step as a solid block from the ground up. The bottom block is one rise tall, the next is two, and so on.
- Add up the blocks and add 10%. Then divide by 0.6, the cubic feet in an 80 lb bag.
Bottom step: 4 × 0.917 × 0.583 = 2.14 cubic feet
Step 2: 4 × 0.917 × 1.167 = 4.28 cubic feet
Top step: 4 × 3 × 1.75 = 21 cubic feet
Total: 27.42 + 10% = 30.16 cubic feet
30.16 ÷ 0.6 = 50.3, so 51 bags of 80 lb
The IRC rules for steps
The IRC is the US home building code. These are its stair rules.
| Rule | Limit |
|---|---|
| Tallest riser (step height) | 7¾ in |
| Shallowest tread (step depth) | 10 in |
| Narrowest stairs | 36 in |
| Landing depth, top and bottom | 36 in |
| Most rise in one flight | 12 ft 7 in (19 risers of 7¾ in) |
| Handrail needed at | 4 or more risers |
| Most difference between risers | ⅜ in |
The stair rules cover steps that serve a house, porch or deck. They don't cover garden steps.
The IRC and other sources differ:
- Outside a door, the IRC lets the landing sit up to 7¾ in below the sill. (That is if the door doesn't swing over it.) Quikrete says 7½ in.
- South Carolina allows masonry steps up to 8 in tall. The model IRC does not.
The calculator warns you when a size breaks an IRC rule. For steps to a house, check your local building rules or ask a builder or engineer.
Quikrete's step sizes
Quikrete's project sheet pairs each riser height with a tread depth. The lower the riser, the deeper the tread.
| Riser | Tread |
|---|---|
| 4–4½ in | 18–19 in |
| 5–5½ in | 16–17 in |
| 6–6½ in | 14–15 in |
| 7–7½ in | 10–11 in |
Every pair here fits the IRC limits.
- Steps for homes are usually 48 in wide, or at least as wide as the door and walk.
- Split tall flights with a landing every 5 ft of rise. Make it at least 3 ft deep.
- Tilt each tread forward about ¼ in per foot, so water runs off.
The calculator starts at a 7 in rise and an 11 in run. That fits both the IRC and Quikrete's chart.
How we work out the volume
No maker gives a way to measure steps. So we use our own geometry. Each step is a block from the ground up.
The bottom block is one riser tall. The next is two risers tall, and so on. The top block is as deep as your landing. We add up the blocks.
| Steps | Height | Cubic feet | 80 lb bags | Weight |
|---|---|---|---|---|
| 1 | 7 in | 7 | 13 | 980 lb |
| 2 | 14 in | 16.1 | 30 | 2,259 lb |
| 3 | 21 in | 27.4 | 51 | 3,838 lb |
| 4 | 28 in | 40.8 | 75 | 5,717 lb |
| 5 | 35 in | 56.4 | 104 | 7,894 lb |
Bags have 10% extra. Weight has none. From 4 risers, the IRC asks for a handrail.
Quikrete's tip: Fill low areas inside the forms with gravel, broken brick or block pieces to use less concrete. Our count is for solid concrete, so rubble will leave you some spare.
Weight and strength
Our weights use Quikrete's figure: about 140 lb for each cubic foot. The 3 steps above weigh about 3,838 lb.
The IRC sets the strength of outdoor steps by how hard the weather is:
- Very little (negligible) weathering: 2,500 psi.
- Moderate weathering: 3,000 psi, air-entrained (with tiny air bubbles).
- Severe weathering: 3,500 psi, air-entrained (with tiny air bubbles).
The Virginia ready-mix group points to a stricter rule. ACI 332 asks for 4,500 psi, air-entrained, where steps freeze and thaw. That is more than the IRC's 3,500 psi. Ask your plant for the mix that fits your area.
Questions people ask
How do you calculate concrete for steps?
Treat each step as a solid block down to the ground. Multiply width × depth × height for each block, in feet. Add the blocks together. For cubic yards, divide the total by 27.
How many bags of concrete for a step?
One step 4 ft wide, 7 in tall and 11 in deep takes 4 bags of 80 lb. That has 10% extra.
How much do concrete steps weigh?
Concrete weighs about 140 lb per cubic foot, says Quikrete. Take 3 steps 4 ft wide, with a 7 in rise, 11 in run and 36 in landing. They weigh about 3,838 lb, or 1.9 tons.
How much does the concrete for steps cost?
Take 3 steps 4 ft wide, with a 7 in rise, 11 in run and 36 in landing. With 10% extra, they need 51 bags of 80 lb, about $331. That is at $6.49 a bag, the middle of 9 stores (6 checked by hand) in Oct 2026. We have no prices for ready-made steps.
What is the tallest a step can be?
7¾ in, says the IRC. South Carolina lets masonry stairs go to 8 in. Garden steps are not covered.
How wide should concrete steps be?
For steps to a house, porch or deck, at least 36 in, says the IRC. Quikrete says steps for homes are usually 48 in wide, or at least as wide as the door and walk.
When do steps need a handrail?
On steps to a house, porch or deck, the IRC asks for one at 4 or more risers. It must be on at least one side.
Do concrete steps need a landing?
At an outside door, usually yes. The IRC asks for a landing at least 36 in deep. At a door other than the main exit, 2 risers or fewer may skip the top landing. (The door must not swing over the steps.)
Where our numbers come from
- Stair rules: US home building code (IRC R311)
- Garden steps are not covered: ICC commentary on the 2021 IRC
- South Carolina change: masonry stair risers up to 8 in
- Building concrete steps: Quikrete project sheet
- Bag sizes and weight: Quikrete Concrete Mix data sheet
- Extra for spills: Sakrete slab calculator (10%)
- Concrete strength by use: US home building code (IRC Table R402.2)
- Steps and drives in freeze–thaw areas: Virginia Ready-Mixed Concrete Association (ACI 332)
- Bag price: the middle price of 9 US stores (Oct 2026)
- Truck price: the middle price of 5 US concrete sellers (Oct 2026)
- Small-order fee: the middle of 4 US cost guides (2026)
Made by BuildersCount. Last checked 3 Oct 2026.
How we work out our numbers About us Found a mistake? Tell us