Twelve calculators for the operations decisions nobody has a spreadsheet for.

Single-file HTML. No install, no signup, no tracking, MIT licensed. Built while running a $40M P&L across nine countries — these are the models I kept rewriting at every job.

$40M
P&L owned
9
countries operated
12
years in marketplace ops
22
documented cases
Everton Paula — Tampa, FL
Twelve years of marketplace and fintech operations across nine countries. Everything here is MIT licensed — fork it, adapt it, ship it. If a tool is missing something your team needs, open an issue and I'll prioritize it.
Open source · MIT License · View on GitHub · About the toolkit