Financecalendar_todayLast updated: Apr 2026

What is Compound Interest?

/ˈkɒmpaʊnd ˈɪntrɪst/

Interest calculated on both the initial principal and the accumulated interest from previous periods, creating exponential growth over time.
lightbulb

Everyday Example

If you invest £1,000 at 10% annual interest, after year 1 you have £1,100. In year 2, you earn 10% on £1,100 — not £1,000. This snowball effect, repeated over decades, is how ordinary savers become wealthy.

publicReal-World Application

Warren Buffett accumulated 99% of his wealth after the age of 50 — a direct result of compound interest working over 60+ years of investing.
psychology

Did you know?

Albert Einstein reportedly called compound interest the "eighth wonder of the world". The concept dates to ancient Babylon, used in commercial loan calculations over 4,000 years ago.

emoji_objects

Key Insight

Time is the most powerful ingredient in compound interest. Starting to invest just 10 years earlier can double your final wealth.

Want to learn Compound Interest in 60 seconds?

Join 50,000+ learners snacking on knowledge daily.