Atbash

Atbash (א״ת ב״ש) is named after its first two pairs: alef–tav and bet–shin. The alphabet is folded in half, so each letter is replaced by the letter the same distance from the other end. The calculator shows the substituted word and its standard value.

The pairs

Where it appears

The Talmud goes through the alphabet in Atbash pairs (א״ת, ב״ש, ג״ר …) as part of a lesson on the letters (Shabbat 104a). Two verses in Jeremiah are read this way by Rashi:

Final letters are converted to their ordinary form before swapping, and the result is written with a final form at the end of each word where one exists. The value shown is the standard value of the new word: שלום becomes בכפי, which is 112.

Try ששך in the calculator