Calculate Height and Width of a image in JQuery.

Use the JQuery inbuilt functions :

$(<image selector>).height() to calculate the height of the image.
$(<image selector>).width() to calculate the width of the image.

Here <image selector> is the selector of image, you can select the image by its tag,id, class etc.

for ex, 
you can select an image by its id (use #)
$('#imgdesert').height()

you can select an image by its class (use dot '.')
$('.myimage').height()

<script type="text/javascript">

    $(window).load(function () {

        $('#imageheightwidth').html(

            "Image height: " + $('#imgdesert').height() + " <br/> Image width: " + $('#imgdesert').width()

            );

    });

</script>

<body>

    <label id="imageheightwidth" class="myimage"></label><br />

    <img id="imgdesert" src="Desert.jpg" />

</body>



Output:

Image height: 700

Image Width : 800


Notes: if you calculate the Image height & width in $(document).ready event , you will get the Image's height and width both Zero. 
Reason is $(document).ready event fires before the image fully loaded and find no image when calculate the dimensions and will show default value i.e 0

Get Image Size in KB/MB

<body>
    <form id="form1" runat="server">
    <div>
        <asp:FileUpload ID="FileUpload1" runat="server" />
    &nbsp;
        <asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
    </div>
    </form>
</body>


Check Image size, before save to the folder :-

protected void Button1_Click(object sender, EventArgs e)
    {
long fileupload = FileUpload1.PostedFile.ContentLength;
double fileSizeKB = fileupload / 1024.0;                                    // get size in KB
double fileSizeMB = fileupload / (1024.0*1024.0);                   // get size in MB

OR-------------

long fileupload = FileUpload1.FileContent.Length; 
double fileSizeKB = fileupload / 1024.0;
double fileSizeMB = fileupload / (1024.0*1024.0);
}



Check Image size, saved to a location :-

FileInfo fileInfo = new FileInfo(MapPath("c.jpg"));       // 'c.jpg' is the image
double fileSizeKB = fileInfo.Length / 1024.0;