get localstorage size

getLocalStorageSize.js

function getLocalStorageSize () {

	function bytesToSize(bytes) { // from http://scratch99.com/web-development/javascript/convert-bytes-to-mb-kb/
	    var sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
	    if (bytes == 0) return 'n/a';
	    var i = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)));
	    if (i == 0) return bytes + ' ' + sizes[i]; 
	    return (bytes / Math.pow(1024, i)).toFixed(1) + ' ' + sizes[i];
	};

	localStorageSize = null;
		for (var i = 0; i < localStorage.length; i++){
		    localStorageSize += localStorage.getItem(localStorage.key(i)).length;
		}
	localStorageSize = bytesToSize(localStorageSize);
	return 'localStorage is : '+localStorageSize;

}