Building steps for your deck? Enter the total rise from the ground to the deck. You get the number of steps, the riser height, the run and the stringer length.
Your shopping list
5Risers
7.2 inRiser height
4Treads
- Total run3.5 ft
- Stringer length4.61 ft
- StringersAbout 16 in apart4
Most US codes allow a riser up to 7.75 in. Check your local code.
How to use the Deck Stair Calculator
- Measure from the ground to the top of the deck boards.
- Type the tread depth you want. Most codes need 10 in or more.
- Read the risers, treads and stringer length.
The math behind it
Risers = total rise / 7.75 in, rounded up
Riser height = total rise / risers
Total run = (risers – 1) x tread depth
Stringer length = square root of (rise x rise + run x run)
A worked example
What we typed in
- Total rise: 54 in
- Tread depth: 10.5 in
- Stair width: 48 in
What we got
- Risers: 7
- Riser height: 7.71 in
- Treads: 6
- Total run: 5.25 ft
- Stringer length: 6.91 ft
- Stringers: 4
Tips from the job site
- Keep every riser the same height. A difference over 3/8 in can cause trips.
- The top step is the deck itself, so treads are one fewer than risers.
Common questions
How many steps do I need for a 36 in deck?
A 36 in rise needs 5 risers of about 7.2 in each and 4 treads.
What is the maximum riser height?
Most US codes allow up to 7.75 in. Check your local code.
See all Deck Calculators.
Last checked: (worked example and form display).