How many characters should I reserve in my database for storing SHA512 hash?

Question

Column: pwdhash

Type: char

Many web pages give me the bit size, not a character size. Should I use a binary field instead?

Answer 1

64 bytes when stored in BLOB.

128 characters when stored as hex.

~88 characters when stored as Base64.

Answer 2

Yes, you should use a binary field.
A hash is not a string.

Answer 3

For readability reasons, these are sometimes stored as hexadecimal digits (two digits per byte). So 512 bits requires 64 bytes, which would need a char(128) field. If you used a binary field, it would only need 64 bytes.