📈Understand Compound Interest
Turn compound interest from a vague formula into a reliable mental tool — calculate growth over time, apply the Rule of 72 in seconds, and reason clearly about savings, debt, and long-horizon decisions.
Phase 1Why Compounding Bends the Curve
See why compounding bends curves away from lines
Interest on interest bends straight lines into curves
6 minInterest on interest bends straight lines into curves
A dollar today isn't a dollar — it's a small factory
6 minA dollar today isn't a dollar — it's a small factory
Time matters more than rate — by a lot
7 minTime matters more than rate — by a lot
Compounding more often helps less than you'd think
6 minCompounding more often helps less than you'd think
Phase 2Working with the Math
Work the formula, Rule of 72, and real rates
One formula does the whole job: A = P(1 + r/n)^(nt)
7 minOne formula does the whole job: A = P(1 + r/n)^(nt)
The Rule of 72 turns rates into doubling years
6 minThe Rule of 72 turns rates into doubling years
Inflation silently eats your compounding
7 minInflation silently eats your compounding
APR lies; APY tells the truth
6 minAPR lies; APY tells the truth
Debt compounds too — and it compounds faster
7 minDebt compounds too — and it compounds faster
Phase 3Seeing Compounding in the Wild
Apply compounding logic to investing, debt, and scams
Two friends, one decade, wildly different retirements
7 minTwo friends, one decade, wildly different retirements
The minimum payment that never ends
7 minThe minimum payment that never ends
Working backward from the number you actually need
7 minWorking backward from the number you actually need
When compounding claims are too good to be true
7 minWhen compounding claims are too good to be true
Phase 4Your Personal Compounding Plan
Build a compounding plan for one real decision
Build your own compounding model for one real decision
8 minBuild your own compounding model for one real decision
Frequently asked questions
- What's the difference between simple and compound interest?
- This is covered in the “Understand Compound Interest” learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
- How does the Rule of 72 actually work?
- This is covered in the “Understand Compound Interest” learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
- Does compounding frequency really matter that much?
- This is covered in the “Understand Compound Interest” learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
- Why does starting early beat saving more later?
- This is covered in the “Understand Compound Interest” learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
- How does compound interest work against me with credit card debt?
- This is covered in the “Understand Compound Interest” learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
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