This example demonstrates the difference between clientHeight/clientWidth and offsetHeight/offsetWidth:
Click the button to get the clientHeight, clientWidth, offsetHeight and offsetWidth of div.
<!DOCTYPE html> <html> <head> <style> #myDIV {/*from www . j ava2 s . c om*/ height: 250px; width: 400px; padding: 10px; margin: 15px; border: 5px solid red; background-color: lightblue; } </style> </head> <body> <button onclick="myFunction()">Test</button> <div id="myDIV"> <b>Information about this div:</b><br> Height: 250px<br> Width: 400px<br> padding: 10px<br> margin: 15px<br> border: 5px<br> <p id="demo"></p> </div> <script> function myFunction() { var elmnt = document.getElementById("myDIV"); var txt = ""; txt += "Height including padding: " + elmnt.clientHeight + "px<br>"; txt += "Height including padding and border: " + elmnt.offsetHeight + "px<br>"; txt += "Width including padding: " + elmnt.clientWidth + "px<br>"; txt += "Width including padding and border: " + elmnt.offsetWidth + "px"; document.getElementById("demo").innerHTML = txt; } </script> </body> </html>