W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
  $("button").click(function(){
    var txt = "";
    txt += "Width of div: " + $("#div1").width() + "</br>";
    txt += "Height of div: " + $("#div1").height() + "</br>";
    txt += "Outer width of div (margin included): " + $("#div1").outerWidth(true) + "</br>";
    txt += "Outer height of div (margin included): " + $("#div1").outerHeight(true);
    $("#div1").html(txt);
  });
});
</script>
<style>
#div1 {
  height: 100px;
  width: 300px;
  padding: 10px;
  margin: 3px;
  border: 1px solid blue;
  background-color: lightblue;
}
</style>
</head>
<body>

<button>Display dimensions of div</button>

<p>outerWidth(true) - returns the width of an element (includes padding, border, and margin).</p>
<p>outerHeight(true) - returns the height of an element (includes padding, border, and margin).</p>

</body>
</html>