Encrypt and Decrypt md5

Question

I am using code $enrypt=md5($pass) and inserting $encrypt to database. I want to find out a way to decrypt them. I tried using decrypting software but it says the hash should be exactly 16 bytes. is there any way to decrypt it or to make it a 16-byte md5 hash?

My hash looks like this: c4ca4238a0b923820dcc