How Compound Interest Works: $10,000 Over 20 Years (Exact Math)

What happens to $10,000 left alone for 20 years? In this masterclass, Olivia runs the exact math on how compound interest works — $10,000 at 4% becomes $21,911, at 7% it becomes $38,697, and at 10% it becomes $67,275. No stock picking, no trading, no luck — just the compound interest formula FV = P(1+r)^n doing its work. You'll learn how compound interest works step by step: the future value formula explained in plain English, compound vs simple interest ($38,697 vs $24,000 on the same $10,000), the Rule of 72 for doubling your money in your head, what $100/month in monthly contributions really adds ($52,093), why starting investing at 25 vs 35 is worth nearly $74,000, how inflation shrinks nominal gains into real returns, and where some investors consider holding long-term investments — like tax-advantaged retirement accounts — to protect compounding from taxes. Whether you're an investing beginner asking how to grow money, how investing works, or how to start investing for retirement, this video gives you the exact numbers, the formula, and the mental models — all illustrations using historical ballpark rates, not promises of returns. 🔔 Subscribe to Smart Capital for data-driven personal finance breakdowns every day. 🎓 Full masterclass series — Smart Capital: Complete Personal Finance & Wealth Building Masterclass: https://www.youtube.com/playlist?list=PLdqSR1MFEl_s Watch next: https://youtu.be/GCv_2yM5JtI ⏱️ Chapters 00:00 Welcome back to Smart Capital — the $10,000 question 00:27 Your exact payoff for the next 12 minutes 01:12 Subscribe for number-driven investing breakdowns 01:38 The compound interest formula (FV = P(1+r)^n) 02:19 $10,000 over 20 years: 4% vs 7% vs 10% — exact figures 03:26 Compound vs simple interest ($38,697 vs $24,000) 04:20 The Rule of 72 — doubling time in seconds 05:16 Subscribe — the $100/month surprise is next 05:36 What $100, $200, $500/month really becomes 06:48 Starting at 25 vs 35 — the $74,000 cost of waiting 07:59 Inflatio

Added 20 Oct 2026