# Why Entropie is divided by 32 (Seed to MNEMONICS)

I want to create a Seed-Phrase (mnemonics) from entropy. One aspect of `BIP39` is to create the checksum and describes it as follows (Link BIP39):

The mnemonic must encode entropy in a multiple of `32` bits. With more entropy, security is improved but the sentence length increases. We refer to the initial entropy length as ENT. The allowed size of `ENT` is `128-256 bits` First, an initial entropy of `ENT` bits is generated. A checksum is generated by taking the first `ENT / 32`

This thread describes a lot of details but not why divider `32` (or I don't understand it). I am not a cryptographer and I did not find any detailed description why the divider `32` has been chosen. My guess is entropy. But why exactly?

BIP39 uses a dictionary of 2048 words. Each word is indexable with 11 bits (2^11).

The combined entropy and checksum is represented as a sequence of words from the dictionary, and therefore must have a length which is evenly divisible by 11.

If you take any integer N where N mod 32 = 0, then (N + N/32) mod 11 = 0.

So `ENT/32` simply provides the number of bits which must be used for the checksum.