Wheelchair / Scooter Ramp Incline Calculator*Vertical Rise: *(Vertical height of the loading surface to the ground) inches Ramp Length ADA RecommendedRecommended Length (1:12 slope): ft rampRamp Length For ResidentialOccupied Ramp Length (2:12 slope): (Ramp length needed if the wheelchair / scooter is in use with the aid of an able assistant) ft rampUnoccupied Ramp Length (3:12 slope):(Ramp length needed for loading and unloading unoccupied chairs and scooters.) ft ramp