JSFiddle - React, Tailwind, and code Playground
HTML
<div id="boxes">
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
</div>CSS
.box{width:100px;height:100px;background-color:red;float:left;margin:10px 0 0 10px}JavaScript
var boxes_per_line = Math.floor($('#boxes').width() / 110);
//console.log(boxes_per_line);
var total = $('.box').length;
//console.log(total);