This calculator allows you to encrypt and decrypt text with Atbash method
The rule of Atbash cipher is that you have to change n letter of alphabet with m − n + 1 letter, where m - the number of letter in an alphabet.
Here's an example
abcdefghijklmnopqrstuvwxyz (original text)
zyxwvutsrqponmlkjihgfedcba (cipher text)