A dual-height seat riser or booster provides an elevated seating surface for an adult individual when positioned on, for example, a bench or pew surface. The riser includes a pair of sidewalls having upper and lower edges and a seat member fixed offset to a midline so as to be closer to the upper edge of the sidewall and positioned at an angle so as to slope downward. The riser is configured such that when positioned on a bench with the lower edge of the sidewalls down and the front edge of the seat member forward, the seat member is at a first height, approximately 4 to 16 inches, and when the riser is inverted with the upper edge down and the rear edge forward, the seat member is at a second height, approximately 2 to 8 inches.
