Compound Interest Calculator in Euros | Finanz2Go

Explore compound growth, monthly contributions, fees and inflation with a free euro savings calculator. See the annual figures and assumptions.

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Calculators · Saving and growth

Compound interest calculator

What could regular saving add up to? Change the time, contribution and growth assumptions to see how they work together.

Monthly contributions + growthFees and inflation · before taxRuns in your browser
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Your assumptions

Monthly payments are added at the end of each month. Rates are assumptions, not current offers.

Illustrative future value

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Your contributions—
Net growth / loss—
In today’s money—
Balance and contributions by year
Account balanceContributions
View the annual figures
YearContributionsBalanceNet growth / loss
Fabian Beining
Fabian BeiningFounder of Finanz2Go · Updated 26 October 2026

Read the result properly

Your deposits do one job. Growth does another.

The amount you put in is the part you control. The return is an assumption. Separating the two makes the result more useful: you can see how much depends on your saving habit and how much depends on growth that may not happen.

01

Start

Your opening amount goes into the scenario once.

02

Grow

A constant monthly growth factor is applied.

03

Add

Your monthly contribution is added at month-end.

04

Repeat

The same calculation repeats for the selected period.

How the calculation works

We treat the return you enter as an effective annual rate. The annual growth factor after the modelled fee is (1 + return) × (1 − fee). Its twelfth root gives the monthly factor. Each month, the previous balance is multiplied by that factor, then the monthly contribution is added.

“In today’s money” divides the final balance by (1 + inflation) raised to the number of years. It is a purchasing-power scenario using your constant inflation assumption.

What this version leaves out: taxes, tax allowances, trading costs, changing contributions, irregular cash flows and market volatility. Annual fees are modelled as a constant percentage, spread across months. No product recommendation or guaranteed outcome is implied.

One small change worth testing

Keep the return unchanged and increase the monthly contribution. Then put the contribution back and increase the fee. The chart shows why both habits and costs deserve attention – without requiring you to guess next year’s market return.

Questions about this calculator

Is this a German ETF tax calculator?

No. This is a general mathematical savings scenario in euros, before tax. German fund taxation needs a separate calculation. Use our Vorabpauschale calculator for its supported cases.

Can the result fall below my contributions?

Yes. A negative return assumption or fees greater than the growth assumption can produce a modelled loss. A smooth curve does not represent how markets move in real life.

Is the starting example a recommended return?

No. All starting values are editable examples. The calculator does not decide which assumption is suitable for you.

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