Finopact
Savings & planning

Compound interest calculator

Project your savings growth, measure the impact of recurring deposits and see what time could do for your money.

Your projection

Simulate your capital

Adjust every assumption. Your results and chart update instantly.

01

Your assumptions

Change any value to test your scenario.

%
0 %15 %
years
1 years40 years
Advanced options
Estimated ending balance€74,594.83 +€28,595 in interest
Total contributed€46,000.00
Interest earned€28,594.83

Your balance over time

Total balanceContributions
€74,595€37,297€0
Year 0Year 7Year 15

Ending balance breakdown

Effective annual rate: 5.12 %
Starting amount€10,000.00
Deposits€36,000.00
Interest€28,594.83

Indicative projection with a constant return, before tax and fees.

Understand the calculation

Why is compound interest so powerful?

With compound interest, your gains start producing gains of their own. The longer the timeline, the more meaningful this cumulative effect becomes.

01

Time is the first multiplier

Unlike simple interest, which only applies to the starting amount, compound interest applies to both your capital and previously earned returns.

Starting earlier can therefore matter more than making a much larger savings effort later.

02

Recurring deposits spread the effort

Adding money monthly or quarterly steadily increases the base that can earn a return.

The simulator always separates the amount you contributed from the growth it generated.

03

Inflation and purchasing power

A future amount will not buy the same things it buys today. The inflation option converts the ending balance into today's purchasing power for a fairer comparison.

FAQ

Frequently asked questions

The essentials to know before interpreting your projection.

What is the difference between simple and compound interest?

Simple interest is calculated only on the initial principal. Compound interest is calculated on both the principal and the interest already earned.

What return rate should I use?

Use a cautious assumption suited to your savings plan. Historical performance never guarantees future returns, so compare several scenarios instead of relying on one rate.

Are taxes and fees included?

No. Results are before tax and fees. You can lower the annual rate to approximate their impact.

Why account for inflation?

Inflation reduces future purchasing power. Real value shows what the ending balance could represent in today's money.

Are the results guaranteed?

No. This projection illustrates a constant scenario. Actual returns vary and the result is not personalised financial advice.