Standard height range for most toilet paper holders is between 28” and 30” depending on specifications, preference and toilet height.
Determine the location of the toilet paper holder and mark with a permanent pen.
Based on the measurements, mark the holes for the left side mounting plate, where it will be secured to the wall.
Measure from end post to end post on the toilet paper holder to determine the spacing of the mounting plates. (Ours is 6-1/4”.)
Then measure and mark that distance from the original marks for the other mounting plate.
Double check all of the marks for level both vertically and horizontally and draw a precise "+" mark where holes will be drilled.
Insert plastic anchors into the holes. (They're usually provided with the toilet paper holder.) Secure the mounting plates to the wall using the provided screws.
Slide the left side accessory with the pivoting arm on first and then secure the right side accessory by pushing flush against the wall and then down onto the mounting bracket.
Slide the toilet paper roll on to the left side pivot arm.