the file size is returned in bytes.
to show it in kb or MB, you would need to do the math to perform the conversion
177600 bytes is not 178 kb.
there are 1024 bytes to a kb.
177600 bytes is 173.4375 KB
177600 / 1024 = 173.4375
1 Megabyte = 1048576 bytes, so to convert to mega bytes, you would use:
177600 / 1048576 = 0.169372558594