Compound interest calculator, how much your money could grow
How much could your money be worth if you let it grow for years? Choose the asset type, enter what you have, what you would contribute each month, the time frame and a return, and see what comes out of your pocket and what is gains.
500 largest U.S. companies (Apple, Microsoft, Amazon…). The most followed index in the world.
~1,250 companies from 23 developed countries. U.S. accounts for ~73%. The most used index for passive global investing.
Like the MSCI World but also includes emerging markets (China, India, Brazil…). The broadest geographic diversification.
Covers developed and emerging markets. Vanguard uses it as the basis for its global funds.
100 largest non-financial companies on the Nasdaq. Heavy technology weighting. More volatile than the S&P 500.
Listed real estate investment trusts. Equities with periodic dividends. Exposure to real estate without buying a property.
The 50 largest companies in the eurozone (Germany, France, Spain, Netherlands…). The benchmark index for continental Europe.
The 35 largest companies listed in Spain. Heavy weighting in banks, utilities and telecoms. Less diversified than global indices.
The 225 largest companies on the Tokyo Stock Exchange. Asia's benchmark index, with strong exposure to Japanese technology and industry.
Over 1,150 companies from 24 emerging countries: China, India, Brazil, South Korea, Taiwan… Higher growth potential and higher volatility.
Cryptocurrencies
High volatility — no reliable reference for projections. Use the CryptoSens simulator to explore crypto scenarios.
Sovereign debt issued by the national government. The name and yield vary by country and monetary policy.
Fixed-term bank deposit with guaranteed capital. Terms and rates vary by country and institution.
Indicative rates — they vary with each country's monetary policy and do not guarantee future results.
Estimated result
Hypothetical simulation for educational purposes. Past performance does not guarantee future results. This is not financial advice.
How it works
Each month the calculator adds the interest to your accumulated money, and the next month that interest earns interest too. For example, if you start with $1,100, contribute $110 a month for 20 years and we assume 7% a year, you will have contributed $27,500 and would end up with $61,745. The other $34,245 would be gains.
Why time matters so much
At first the interest is small, because it is calculated on little money. Over the years it is also calculated on the earlier interest, which is why the curve speeds up at the end. A quick way to see this is the rule of 72. Divide 72 by the annual return and you get a rough idea of how many years your money takes to double. At 7% that is about 10 years, and at 4%, about 18.
Good to know
- The calculator assumes the same return every year. In reality there are good years and bad years, and an investment can also lose money.
- It does not include taxes, fees or inflation, which reduce what you keep in real life.
- It splits the annual return across 12 months and adds your contribution at the end of each month. That is why 7% a year ends up as 7.23% over a year, since interest builds up every month.
Educational content. This is not financial advice.