Enter the total height from the ground to the top of your deck, and this lays out the staircase — number of steps, exact riser height, total run, and the stringer length to cut.
Most codes require risers of 4 to 7.75 in and treads of at least 10 in. Always check your local building code.
See the How to Build a Deck guide and the Deck Footing Chart.
Laying out deck stairs
Deck stairs are designed from the total rise — the vertical distance from the ground to the top of the deck. Divide that rise by a comfortable step height (codes commonly cap riser height around 7¾ inches) and round to a whole number of steps; the actual riser height is then the total rise divided by that number. Each step's run (tread depth) is typically at least 10–11 inches, and a common rule of thumb is that rise plus run lands near 17–18 inches for comfortable stairs.
The number of treads is one less than the number of risers, and the stringer length follows from the rise and total run by the Pythagorean theorem. Codes also govern handrails, graspable rail dimensions, and maximum riser variation (steps must be uniform, since uneven risers cause trips). Use this calculator to lay out the geometry, then check the specifics against your local code.