Learn / Investing

Compound Interest Calculator: See How Your Money Grows Over Time

By Team arvy · Last updated: March 2026 · Interactive Calculator

Albert Einstein reportedly called compound interest the "eighth wonder of the world." Whether he actually said it is debated — the power of compounding is not. Calculate here how your wealth grows over time.

What Is Compound Interest?

Compound interest means you earn returns not only on your deposited capital, but also on previously earned returns. Your money works for you — and the earnings work for you too. This exponential growth becomes more powerful the longer you stay invested.

A simple example: if you invest CHF 10,000 at 7% return, after one year you have CHF 10,700. In year two, you earn 7% on CHF 10,700 — that's CHF 749 instead of CHF 700. In year three, it's CHF 801. The difference seems small, but over 20 or 30 years, the effect is enormous.

The Three Levers of Compound Interest

Time: The most important factor. The earlier you start, the stronger the effect. 10 extra years of investing can mean the difference between a comfortable and a modest retirement. That's why the best time to start investing is: now.

Consistency: A monthly standing order (dollar-cost averaging) is compound interest's most powerful ally. Even small amounts — CHF 200, 300, or 500 per month — add up to astonishing sums over decades.

Return: The difference between 3% and 7% per year may seem small — but over 30 years, it triples the final wealth. That's why it's important to invest in asset classes with higher return potential, like equities — and keep fees as low as possible.

Why Fees Kill Compound Interest

Fees act as negative compound interest. If you pay 2% per year in fees (as with many Swiss banks), that's not just subtracted from your return — it also reduces the base on which future returns are calculated. Over 30 years, high fees can reduce your final wealth by 30–40%. At arvy, all-in fees are 0.84–1.11% per year — including management, transactions, stamp duty, and tax statement. → Fees in detail

Concrete Examples

Example 1 — Career starter: CHF 0 starting capital, CHF 300/month, 7% return, 35 years = CHF 531,715. Deposited: CHF 126,000. Interest: CHF 405,715 (76%). More than three quarters came from compound interest alone.

Example 2 — Savings plan from age 30: CHF 20,000 starting capital, CHF 500/month, 7% return, 25 years = CHF 513,951. Deposited: CHF 170,000. Interest: CHF 343,951 (67%).

Example 3 — Conservative from age 50: CHF 100,000 starting capital, CHF 1,000/month, 5% return, 15 years = CHF 475,631. Deposited: CHF 280,000. Interest: CHF 195,631 (41%).

Illustration. Not investment advice. Returns are not guaranteed. Past performance is no guarantee of future results. The calculator does not account for taxes, inflation, or fees — actual results may differ. arvy is a FINMA-regulated wealth manager with a CISA license. Imprint & Legal Notice