The vertical interval (V_{i}) for the terraces is the vertical distance from the base of one riser to the base of another riser. The vertical interval is given by

V_{i} = (S × W_{b}) ÷ (100 - S × U)

where S is the slope of the hillside in percent† (not degrees),

W_{b} is the width of the bench, and

U is the slope of the riser as a ratio.

† Percent to degree converter

Degrees are expressed as percent with the following formula.