Deck project planning · Updated November 3, 2026
Deck stair rise and run planner
Show equal rise, horizontal projection, diagonal and angle from your measured rise and chosen stair counts. No code or structural approval.
Enter the measured vertical rise, the rise and tread counts from your own layout, and the horizontal run per tread. The planner shows the equal rise per interval, total horizontal projection, diagonal and angle using only those inputs.
Enter values and calculate.
Measure from the finished deck surface to the top of the landing. Rise intervals and tread runs may differ depending on how the top deck and bottom landing are counted; enter the counts for your own plan. This is arithmetic only. It does not choose code dimensions, check local requirements, size or detail stringers, account for board thickness or connections, or approve a stair design.
Sources and method
- Decks.com: How to Lay Out Deck Stair Stringers (reviewed November 3, 2026): describes measuring total rise from the deck surface to the stair landing and using the rise/run measurements in a layout. Its installation instructions also discuss stringer and tread details that this arithmetic planner does not model.
Method: rise per interval = total vertical rise ÷ entered rise intervals; total projection = entered tread count × horizontal run per tread; diagonal = square root of (total rise² + projection²); angle = arctangent(total rise ÷ projection). Counts are entered independently so the tool does not assume whether the deck or landing is counted as a tread.
How it works
Measure vertical rise from the finished deck surface to the top of the landing. Enter the rise interval count, tread count and tread run from your own layout. The result shows per-interval rise, horizontal projection, diagonal and angle. Counts remain separate because the top deck or bottom landing may be counted differently. This is arithmetic only, not a code or structural design check.
Good to know
Quick answer: how do I calculate deck stair rise and run?
Divide measured total vertical rise by the rise interval count you selected to see the average rise per interval. Multiply tread count by horizontal run per tread for the total projection. The straight-line diagonal is the square root of total rise squared plus projection squared. Decks.com describes measuring from the deck surface to the landing and laying out rises and runs. Reviewed November 3, 2026. This planner does not determine required dimensions or approve a layout.
Where should I measure total rise?
Measure vertically from the finished deck surface to the top of the landing where the stairs will meet it. Decks.com describes this measurement for stair layout. Enter rise and tread counts independently to reflect how your plan handles the deck surface and landing.
Why are rise and tread counts separate?
The number of vertical intervals and horizontal treads may differ based on how the top deck and bottom landing are counted. Enter the counts from your plan; the calculator does not infer a convention or layout.
Does this check building code or size stringers?
No. It reports geometry only. It does not choose allowable rise or run, check local code, account for tread or finish thickness, specify stringer cuts or connections, or size structural members. Confirm the plan with the relevant local authority and qualified project professionals.
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