Compound interest calculator for investments

Broad world stock indices have grown roughly 8 to 9% a year before inflation over long periods: the MSCI World index (developed markets, dividends reinvested, in US dollars) returned about 8.5% a year from the end of 1987 to April 2025, according to MSCI's factsheet, with big swings from one year to the next. That average spans almost four decades with deep falls and long rises; it describes the past, comes before fees, tax and inflation, and does not predict future returns. 10% is above it, and no future return is known in advance. Try lower rates, or the presets for a savings account or bonds. Past returns do not promise future ones.

Prices tend to rise, so an amount in 30 years pays for less than the same amount today. With inflation switched on, every result is divided by how much prices have risen by that year, so it shows what the money would be worth at today's prices. At 2.5% inflation, a balance of 471,935 in 30 years is worth about 224,992 in today's money. Your statement would still show the bigger number.

A fee is taken every year from your whole balance, and the money taken also stops growing. On a plan of 1,000 plus 200 a month at 10% for 30 years, a 0.2% yearly fee costs about 19,987, around 4% of the result. An expensive fund charging 1.8% a year plus entry, exit and performance fees could take about 219,894, close to half. Switch on fund fees to see the effect on your own plan.

Taxed every year works like interest on a savings account: gains are taxed as they arrive, so less money stays invested to compound. Taxed when you sell is typical for accumulating funds: gains grow untaxed and tax is due once, on the gain, when you sell. On the default plan at 19%, yearly tax costs about 156,475 and tax at the end about 75,798. Rules differ by country, so this is an estimate, not tax advice.

Pick how often your account adds interest: most savings accounts and funds work monthly, bonds often pay twice a year, and some accounts credit interest daily. The effective yearly rate under the select shows what the nominal rate really becomes over a year. At 7% a year, monthly compounding gives 7.23% and daily compounding 7.25%; at 5% the figures are 5.12% and 5.13%. The difference between monthly and daily is small, but yearly versus monthly adds up over decades. If you do not know, keep monthly: it is what most products and this site's examples use. Tap any option and the chart updates.