jQuery(document).ready(function($) { var lcol_height = $("#leftCol").height() + 80; // add 80 for margin + padding var rcol_height = $("#rightCol").height(); if(rcol_height > lcol_height) $("#leftCol").css('height',(rcol_height - 80) + 'px'); else $("#rightCol").css('height',lcol_height + 'px'); });