Deck Stairs Calculator
Building stairs for your deck is often considered “the most difficult part of” the construction project. Having the right calculations before getting started can make the task a lot easier.
To simplify the process, we’ve created this deck stair calculator to help you determine the correct measurements needed to carry out your project. Once you’ve calculated the number of steps, you’ll then need to know how to build stairs for your deck.
This calculator will tell you:
- How Many Rises You'll Need
- Dimensions for each rise
- Total run and rise
- Step run (tread depth)
- step rise (riser height)
- bottom step rise
- angle of your staircase
- stringer length
- How Many Rises You'll Need
- Dimensions for each rise
- Total run and rise
- Step run (tread depth)
- step rise (riser height)
- bottom step rise
- angle of your staircase
- stringer length
Your Stairs Calculator Results
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What Are the Parts of a Deck Staircase?
Knowing the lingo behind the parts that make up a staircase can go a long way toward taking accurate measurements and simplifying the process.
Use the calculator to add your deck’s measurements for:
- 5 Total rise (height from the top of your deck to the ground at the bottom end of the stringer or the total run)
- 6 Step Run (horizontal tread depth) for each stair
- 7 Tread type (whether you’ll use a single board or two smaller boards to create a stair tread)
- 8 Stringer attachment style (whether you plan to use an outside frame or a flush frame)
How to Calculate Stair Stringers
Having a stable, sturdy set of stairs leading to and from your deck is one of the most important—and complex—parts of the deck building process. To calculate the stringer length, follow this formula:
(run)2 + (stair rise)2 = [square root of your total]
Want to learn more? Check out our article, Building Deck Stairs and Steps, to find find and tricks to help make your deck building project run more smoothly.