Java Script util function to get bytes of file size from KB and MB

var convetFileSizeInBytes= function (size) { var totalSize=0; var kilobyte = 1024; var megabyte = kilobyte * 1024; if(size.indexOf("b")>0){ totalSize=size.replace('b',''); } if(size.indexOf("KB")>0){ totalSize=size.replace('KB',''); totalSize= Math.round(totalSize*kilobyte); } if(size.indexOf("MB")>0){ totalSize=size.replace('MB',''); totalSize= Math.round(totalSize*megabyte); } return totalSize; }; call above if ur inputs like this convetFileSizeInBytes("10KB"); you will get byte values and you can use that for validation