You can use Bootstrap sizing classes to set height or width of the row (or any other element).

Note: The height of the row (or any other element) will be relative to the height of its parent. That means if you set 100px height to the parent of the row, and then you will set the height of the row to 50%, the row will be 50px height.

Detailed documentation and more examples you can find in our Bootstrap Sizing Docs

Basic example

The red div below is 100px height and all the child element are relative to it.

Height 25%
Height 50%
Height 75%
Height 100%
Height auto

      <div style="height: 100px; background-color: rgba(255,0,0,0.1);">
        <div class="h-25 d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1);" style="width: 120px; background-color: rgba(0,0,255,.1);">Height 25% </div>
        <div class="h-50 d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1);">Height 50%</div>
        <div class="h-75 d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1);">Height 75%</div>
        <div class="h-100 d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1);">Height 100%</div>
        <div class="h-auto d-inline-block" style="width: 120px; background-color: rgba(0,0,255,.1);">Height auto</div>
      </div>