startinvesting.ai

Learn

Personal finance, explained with numbers

No vague advice. No jargon. The math behind building wealth — and exactly how to apply it.

Investing7 min read

How Much Should I Invest Per Month?

The honest answer — with real dollar examples at every income level and timeline.

FIRE8 min read

The 4% Rule: How Much Do You Actually Need to Retire?

The math behind the most important retirement number — and how to calculate yours in 30 seconds.

Investing6 min read

Compound Interest: How $500/Month Becomes $1.7 Million

Exact outcomes for $100, $300, $500, and $1,000/month — starting at 25, 35, and 45.

FIRE7 min read

Coast FIRE: The Number That Lets You Stop Investing Early

What Coast FIRE is, how to calculate your number, and why it changes how you think about work.

Mortgage7 min read

30-Year vs. 15-Year Mortgage: Which Saves More Money?

Side-by-side with real numbers — total interest, monthly payments, and the invest-the-difference math.