BPM Calculator

by Hensixteen

HTML

<html>
  <center><h1>
  Welcome! Please press the button according to your heartbeat to fi     nd out what your BPM is
  </h1>
  
  <br>
  <br>
  <br>
  
  <button onclick="updateHeartRate()">
  One Heartbeat
  </button>
  
  <br>
  <br>
  
  <p id="heartrate"></p>
  </center>
  
  <script>
  	var totalBeats = 0;
    var firstClick = true;
    var difference = 0;
    var bpm = 0;
    
    function updateHeartRate() {
    
    	var d = new Date();
		totalBeats++;
    
    	if(firstClick == true) {
			difference = d.getTime();
			firstClick = false;
      }
   
   		t = (d.getTime() - difference)/1000
		bpm = Math.round(totalBeats * (60 / t));
      
    	document.getElementById("heartrate").innerHTML = bpm;
    
    }
  </script>
</html>