Ohio Administrative Code|Rule 4501-43-04 | Specifications.

                                                
(A) The horizontal bumper shall be at least 4.5 inches in vertical height, centered on the vehicle's centerline, and extend no less than the width of the respective wheel track distances. Bumpers shall be horizontal load-bearing bumpers and attached to the vehicle frame to effectively transfer impact when engaged.
(B) Maximum bumper heights shall be determined by  the type of vehicle at time of manufacture. If other than a  passenger vehicle, the maximum bumper height shall be determined by the gross  vehicle weight rating (GVWR) at the time of manufacture. The height shall be measured in terms of the vertical distance between the ground and the bottom of the  bumper. Maximum bumper heights are as follows:
Bumper Height
FRONT
REAR
Passenger vehicles
 22 inches
22 inches
All other vehicles
4,500 lbs. and under GVWR 
24 inches
  26 inches
4,501 lbs. to 7,500 lbs. GVWR
27 inches
  29 inches
7,501 lbs. to 10,000 lbs. GVWR 
28 inches
 31 inches
(C) If the body and/or truck bed height is altered, the difference in height between the body floor and/or the truck bed floor to the top of the frame rail shall not exceed four inches.
(D) For any vehicle with bumpers or attaching components which have been modified or altered from the original manufacturer's design in order to conform with the maximum bumper requirements of this rule, the bumper height shall be measured from a level surface to the bottom of the vehicle frame rail at the most forward and rearward points of the frame rail.
Frame Rail Height if bumper modified or altered
Front
Rear
Passenger vehicles
22 inches
22 inches
All other vehicles
4,500 lbs. and under GVWR
24 inches
26 inches
4,501 lbs. to 7,500 GVWR
27 inches
29 inches
7,501 lbs. to 10,000 lbs. GVWR
28 inches
31 inches
(E) The height restriction in this rule applies to the distance from the ground to the bottom of the frame rail under any one or more of the following conditions:
(1) A motor vehicle is not equipped with a front and rear bumper.
(2) The bumper height relative to the frame rails has been altered.
(3) A supplemental bumper has been installed or an addition to the original or replacement has been made.