JSFiddle - React, Tailwind, and code Playground

HTML

<strong class="weight-800">800 KG</strong>

CSS

#populate {
    border: 1px solid red;
}

JavaScript

jQuery(document).ready(function () {
    $('[class^="weight"]').each(function () {

        var usingMetric = false;

        var $this = $(this);
        var value = this.className.split('-')[1];
        if (usingMetric) {
            $this.text(value + " KG");
        }
        else {
            value = parseFloat(value) * 2.20462262; // Convert to imperial
            $this.text(value + " lbs");
        }
    });
});