How stair math works
Divide the total rise by a comfortable riser height (~7.5″) and round to a whole number of steps — you can't have a partial step. Then divide the rise by that number of steps to get the exact riser height so every step is equal. The total run is the number of treads times the tread depth. Most building codes cap riser height around 7¾″ and require a tread depth of at least 10″, with all risers within ⅜″ of each other.
Always verify against your local building code before building.