JSFiddle - React, Tailwind, and code Playground

HTML

<div class="action_bar">
&nbsp;
</div>

CSS

.action_bar
{
 background-color: #000000;
width: 400px;      
color: #ffffff;    
}

JavaScript

jQuery("body").append("<div id='dpi_test' style='height: 1in; left: -100%; position: absolute; top: -100%; width: 1in;'></div>");


jQuery(document).ready(function(){

    dpi_x = document.getElementById('dpi_test').offsetWidth;
    dpi_y = document.getElementById('dpi_test').offsetHeight;

    dp_to_pixel_x = 1 * (dpi_x / 160);

    dp_to_pixel_y = 1 * (dpi_y / 160);

    action_bar_height = (dp_to_pixel_y * 48);

    jQuery(".action_bar").css("height", Math.round(action_bar_height) + "px");
    jQuery(".action_bar").html(dpi_y + "px");

});