Floor-to-floor total rise and desired riser height (same units)—step count = ceil(rise / riser).
Given total rise and a maximum allowed riser height (both positive), the tool uses n = ⌈total rise ÷ max riser⌉ steps, then shows an equalized riser height total rise ÷ n (three decimals). This is a layout approximation, not a building‑code compliance check.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.