public static String calculateTotalSize(List<String> sizeList) {
        double sizeKB = 0;

        for ( String strSize : sizeList ) {
            String [] tokens = strSize.split(" ");

            if ( tokens[1].toLowerCase().equals("mb") ) {
                sizeKB+= Double.valueOf(tokens[0]) * 1024.0;
            } else if (tokens[1].toLowerCase().equals("gb")) {
                sizeKB+= Double.valueOf(tokens[0]) * 1024.0 * 1024.0;
            } else if (tokens[1].toLowerCase().equals("kb") ) {
                sizeKB+= Double.valueOf(tokens[0]);
            }
        }

        StringBuilder totalSizeBuilder = new StringBuilder("");

        DecimalFormat df = new DecimalFormat("#.##");

        if ( sizeKB < 1024.0 ) {
            totalSizeBuilder.append(df.format(sizeKB));
            totalSizeBuilder.append(" KB");
        }
        else if ( sizeKB < 1024.0 * 1024.0 ) {
            totalSizeBuilder.append(df.format(sizeKB / 1024.0));
            totalSizeBuilder.append(" MB");
        }
        else {
            totalSizeBuilder.append(df.format(sizeKB / ( 1024.0 * 1024.0)));
            totalSizeBuilder.append(" GB");
        }

        return totalSizeBuilder.toString();
    }