As an Amazon Associate I earn from qualifying purchases.
What a set of deck stairs costs by height, width, material and railing.
With these inputs:
| Result | Value |
|---|---|
| Installed cost of the stairs | $548 – $1,017 |
| Steps | 5 risers, 4 treads |
| Rise per step | 7.20 in |
| Total run | 3 ft 6 in |
| Stringers | 4 at 16 in on centre |
| Stair structure and treads (4 steps) | $380 – $680 |
| Stair railing (1 × 5.6 ft) | $168 – $337 |
IRC limits: riser no more than 7¾ in, tread at least 10 in, width at least 36 in. A graspable handrail is required once the stair has four or more risers, and a guard on any open side more than 30 in above grade. Composite and PVC treads need stringers at 12 in on centre; wood usually allows 16 in.
Deck stairs are priced by the step, and the step count comes from the height of the deck. This works out the number of risers at a comfortable 7 inches or so, the stringers the width needs, the stair railing on one or both sides, and an optional concrete landing pad — then prices the set in pressure-treated wood, cedar, composite or PVC.
As a planning range, pressure-treated deck stairs cost about $95–$170 per step installed for a 4 ft wide stair, composite about $175–$300 per step, before railing. A 36 in high deck needs five risers and four treads, so a basic wood stair with a handrail on one side lands around $550–$1,020.
Divide the height from the ground to the top of the decking by about 7.5 in and round up — that is the number of risers. There is always one fewer tread than risers because the deck itself is the top step.
Under the IRC a stair with four or more risers needs a handrail on at least one side, 34–38 in above the tread nosings. Any open side more than 30 in above the ground also needs a guard.
The code minimum is 36 in. Four feet lets two people pass and fits most furniture; wide sweeping stairs of 6–8 ft turn the steps into seating but need more stringers and cost more.
Need the whole roof at once? The free roofing calculator works out roof area, squares, shingle bundles, underlayment, drip edge, ridge cap and installed cost from one set of measurements.