Why Starting to Invest Early Wins
Time is the most powerful variable in investing. See why starting early beats starting big, with worked examples and a simple plan to start today.
The Rule of 72: Double Your Money Math
The Rule of 72 estimates how long it takes to double your money at any rate. Learn how it works, why it works, when it breaks, and how to use it.
Compound vs. Simple Interest: The Difference
Compound and simple interest can produce wildly different results. Learn the formulas, see side-by-side examples, and know which one applies to you.
How Compound Interest Works (With Examples)
A plain-English guide to how compound interest works: the formula, how compounding frequency affects returns, and real worked examples you can reproduce.
Ready to Run Your Own Numbers?
Project your savings growth with contributions, compounding frequency, inflation, and tax — all in your browser.
Open the Compound Interest Calculator