Chart.js Number Format
Answer : There is no built-in functionality for number formatting in Javascript. I found the easiest solution to be the addCommas function on this page. Then you just have to modify your tooltipTemplate parameter line from your Chart.defaults.global to something like this: tooltipTemplate: "<%= addCommas(value) %>" Charts.js will take care of the rest. Here's the addCommas function: function addCommas(nStr) { nStr += ''; x = nStr.split('.'); x1 = x[0]; x2 = x.length > 1 ? '.' + x[1] : ''; var rgx = /(\d+)(\d{3})/; while (rgx.test(x1)) { x1 = x1.replace(rgx, '$1' + ',' + '$2'); } return x1 + x2; } Put tooltips in 'option' like this: options: { tooltips: { callbacks: { label: function(tooltipItem, data) { return tooltipItem.yLabel.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,'); } } ...