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Compound Interest Calculator

Project long-term ETF & stock growth — see the power of compounding.
Your investment plan
Results
Final total assets
Total contributed
Total gains
Total return
Lower = principal, upper = gains — compounding grows the green part faster over time.
How compounding works

Compound interest means your gains are reinvested and earn more gains. The growth curve becomes exponential — the longer you invest (10, 20+ years), the more dramatic the effect.

Recurring investing (dollar-cost averaging) means investing a fixed amount on a fixed schedule. It averages your entry cost and removes the risk of buying everything at the top — ideal for busy people.

FAQ
What annual return is reasonable?

Use a conservative number close to long-term averages: broad-market ETFs ~8%, high-dividend ~6%, bonds ~5%. Over-optimistic rates badly overestimate results.

Does recurring investing guarantee profit?

No. It lowers timing risk but not market risk. Past performance doesn't predict the future — hold long-term and diversify.

Is it free?

Yes — completely free and runs locally in your browser.

About this compound interest calculator

Compound interest is how savings and investments grow exponentially — you earn returns on your past returns. This calculator projects how a starting amount plus regular contributions can grow over time, with an interactive chart, in five languages.

How to use

  1. Enter your starting (principal) amount.
  2. Add a regular contribution and choose monthly or yearly.
  3. Set an expected annual return rate and the number of years.
  4. Read the projected balance and the growth chart.

Why use it

Seeing the curve makes the value of starting early tangible. Small, consistent contributions compounded over decades often outperform a single large deposit. Use it to plan a retirement fund, an emergency fund, or any long-term goal.

FAQ

What return rate should I enter?

Use a realistic long-term figure. Broad stock-market averages have historically been around 6-8% before inflation, but past performance does not guarantee future results.

Does it account for inflation or tax?

No — results are nominal. Subtract your expected inflation and tax to estimate real-terms value.

Is this financial advice?

No. It is an educational projection tool. Consult a qualified professional before making real financial decisions.

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