piece-length finds the optimal piece length for a given number of bytes. Optimal for what exactly? BitTorrent. VuzeWiki and TorrentFreak have both released some examples of ideal piece lengths, and this algorithm will reproduce them.

npm install piece-length

note: you may need to polyfill Math.log2

var optimum = require('piece-length')

// 350mb should be 256kb
optimum(367001600) // => 262144

MIT