2👍
If you could share some of your code that would help quite a bit, but not having used Chart.js I did some searching and found this:
https://jsfiddle.net/cmyker/ooxdL2vj/
Chart.pluginService.register({
beforeDraw: function(chart) {
var width = chart.chart.width,
height = chart.chart.height,
ctx = chart.chart.ctx;
ctx.restore();
var fontSize = (height / 114).toFixed(2);
ctx.font = fontSize + "em sans-serif";
ctx.textBaseline = "middle";
var text = "75%",
textX = Math.round((width - ctx.measureText(text).width) / 2),
textY = height / 2;
ctx.fillText(text, textX, textY);
ctx.save();
}
});
Hope this helps!
Source:stackexchange.com