diff --git a/lib/cpu-usage.js b/lib/cpu-usage.js
new file mode 100644
index 0000000..1b58a0d
--- /dev/null
+++ b/lib/cpu-usage.js
@@ -0,0 +1,20 @@
+let startTime  = process.hrtime()
+let startUsage = process.cpuUsage()
+
+module.exports = () => {
+	function secNSec2ms (secNSec) {
+	  return secNSec[0] * 1000 + secNSec[1] / 1000000
+	}
+
+	var elapTime = process.hrtime(startTime)
+	var elapUsage = process.cpuUsage(startUsage)
+
+	var elapTimeMS = secNSec2ms(elapTime)
+	var elapUserMS = elapUsage.user
+	var elapSystMS = elapUsage.system
+
+	startTime = process.hrtime();
+	startUsage = process.cpuUsage();
+
+	return Math.round(100 * ((elapUserMS + elapSystMS) / 1000) / elapTimeMS)
+}
\ No newline at end of file