Free tools

Investing Tools & Calculators

Simple, no-login calculators that run entirely in your browser. Nothing is saved or sent to a server — enter your numbers and get an answer instantly.

Why we built these

MinMaxDoc's full engine builds a tax-aware, mean-variance–optimized set of buy and sell recommendations for your real portfolio. These free calculators are a lightweight taste of that thinking: the rebalancing tool does the arithmetic of getting back to target, and the Monte Carlo simulator shows why a single "average return" number hides an enormous range of real-world outcomes.

They deliberately run client-side and never touch your account, so you can use them freely and anonymously. When you want a full second opinion tuned to your holdings, tax lots, and preferences, that lives one free account away.

Get a full tax-aware second opinion — free

Create a free MinMaxDoc account and get personalized, tax-aware buy & sell recommendations for your actual portfolio — mean-variance optimized, lot-level aware, and yours to act on.

Optimize my portfolio →