#compound-interest

$100/month feels too small to bother with. But run it through 30 years of compounding and the number lands at $122K. Plus the harder lesson: starting at 25 with $100 beats starting at 35 with $200.

Lump sum $50K at 7% turns into $381K in 30 years. Add $500/month and it hits $988K. But inflation cuts that nominal $988K down to $406K of real purchasing power. Both numbers matter.

Compound interest is just earning returns on returns. The math is simple. The reason it's powerful — and the reason most people get it wrong — is that the curve barely moves for the first 10 years.

The same monthly amount, the same return, just a 10-year head start. We ran the compound-growth math to show exactly what 'time in the market' is actually worth in dollar terms.

We isolated the one variable that actually matters — reinvest or pocket — by holding share-price appreciation equal on both paths. Just the dividend snowball, run on a $10,000 starting portfolio with $200/month contributions.

A refund feels like a bonus. Mechanically, it's the government returning your own over-withheld money without paying interest on the float. We ran the compound-growth cost of that pattern.

We ran the future-value-of-annuity math on starting now versus starting in 12 months, both ending at the same date. The gap isn't from the missing 12 payments alone — it's the compounding those payments never got to do.

The education-fund math works backward from your target: instead of asking 'what will my savings grow to,' it solves the compound-interest formula for the monthly contribution that actually gets you there.