But i would strongly recommend to take into consideration the height and physical capabilities of the person you are installing these grab bars for.
Residential ada shower grab bar height.
Controls shall be located on the back long wall 27 inches 685 mm from the side wall.
Grab bars shall be installed 6 inches 150 mm maximum from adjacent walls.
The controls shall be placed in an area between 38 48 inches 965 1220 mm above the floor.
The problem is that installers often aim for one edge of the range and end up a bit high or low.
The grab bar or bars shall be 33 36 inches 840 915 mm high.
For horizontal grab bars the ada standards require a height between 33 and 36 inches from the finished floor of the bathroom shower or tub.
Grab bars shall not be provided above the seat.
In a transfer shower the bottom of the vertical bar must be 3 to 6 inches above the horizontal bar on that wall.
Figure 608 3 3 grab bars for alternate roll in type showers.
It is helpful to use this range as a guide for placement but the most important part is selecting a height that feels comfortable and secure for the person using them.
Grab bars in shower stall requirements transfer type shower compartments transfer type shower compartments shall be 36 inches 915 mm by 36 inches 915 mm clear inside dimensions measured at the center points of opposing sides and shall have a 36 inch 915 mm wide minimum entry on the face of the shower compartment.
This is a good starting range.
A folding or non folding seat shall be provided in transfer type shower compartments.
Generally grab bars should be installed at whatever height is most appropriate for their primary user.
Make sure to check the weight limit before you buy a grab bar.
The shower head and control area may be located on the back wall or on either side wall.
Grab bars come in a variety of sizes some are as small as nine inches or as long as 36 inches.
Each grab bar shall be 24 inches 610 mm long minimum and shall be installed 24 inches 610 mm maximum from the head end wall and 12 inches 305 mm maximum from the control end wall.
However ada standards recommend that rear grab bars be installed at the height of between 33 and 36 inches above the finished floor of the tub shower or bathroom.
A 42 inches 1065 mm minimum length grab bar is required on the side wall spaced a maximum of 12 inches 305 mm from the back wall and extending a minimum of 54 inches 1370 mm from the back wall at a height of 33 36 inches 840 915 mm.
Typically grab bars in the shower should be installed 33 to 36 inches from the floor of the bathroom this is according to ada americans with disabilities act standards.