All Calculators

Notes from a skeptical saver.

Essays on investing, behavior, and math — written for myself, posted for anyone who cares.

investingasset allocationretirementpersonal finance

Your Portfolio Should Age With You

The allocation shift most investors make too late — and a decade-by-decade framework to get ahead of it

There's no single right allocation — but there is a direction of travel. Here's the decade-by-decade framework I wish I'd had from the start, and why the $100K milestone changes the math entirely.

May 3, 2026
5 min
investingroth iraretirementpersonal finance

Dear Younger Me: Just Open the Roth IRA

Why the Roth IRA is the best gift your younger self can give your older self

I dropped $7,000–$14,000 into a Roth IRA early in my career, picked a boring S&P 500 ETF, and forgot about it. Fifteen years later it's worth over $40,000 — entirely tax-free. Here's what I'd tell my younger self.

April 27, 2026
4 min
investingstockslessonsbeginner

Early Mistakes Are Less Expensive

What losing 85% on GE taught me about ego, timing, and when to walk away

I bought GE in the $30s, then the $20s, then kept buying all the way down to $5. What that 85% loss taught me about ego, laziness, and why the most expensive investing mistakes are the ones you make late.

April 18, 2026
7 min
investinghsapersonal financehealth

Health is Wealth; Literally

The triple-tax-advantage account most people ignore — and why staying healthy is the best financial strategy

A friend's $100K HSA balance changed how I think about money. The account most of us scroll past during open enrollment might be the most powerful wealth-building tool in the tax code — and it compounds even better when you stay healthy.

April 12, 2026
6 min
investingteslaevtechnology

My Love with FSD

A 1,400-mile Tesla road trip, and what it taught me about pricing an experience

A 1,400-mile Tesla road trip from the Bay Area to Seattle — and what a rainstorm near Medford taught me about pricing an experience, evaluating Tesla as an investment, and asking better questions than P/E ratios.

April 11, 2026
7 min