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Inflation calculator

Inflation calculator: what your euros will be worth

Enter an amount, an inflation rate and a horizon to see the purchasing power of cash in today's euros, compared with the same money invested at a return you choose.
Real loss (cash)-€4,463today's purchasing power
Real gain (portfolio)€11,426
Accumulated difference€15,889
Formula

€10,000 ÷ (1 + 3 %)^20 − €10,000 = -€4,463

Year by year comparison (in today's €)

YearCash (uninvested)Index portfolioAccumulated difference
1€9,709€10,388€679
2€9,426€10,792€1,366
3€9,151€11,211€2,060
4€8,885€11,646€2,761
5€8,626€12,099€3,473
6€8,375€12,568€4,193
7€8,131€13,056€4,925
8€7,894€13,564€5,670
9€7,664€14,090€6,426
10€7,441€14,637€7,196
11€7,224€15,206€7,982
12€7,014€15,796€8,782
13€6,810€16,410€9,600
14€6,611€17,047€10,436
15€6,419€17,709€11,290
16€6,232€18,397€12,165
17€6,050€19,111€13,061
18€5,874€19,854€13,980
19€5,703€20,625€14,922
20€5,537€21,426€15,889

How the calculation works

The real value of money is its nominal value divided by accumulated inflation: real value = amount ÷ (1 + inflation)^years. At a constant 3%, €1,000 kept for ten years buys what about €744 buys today, because 1.03^10 ≈ 1.344. The invested line applies the chosen return first and then the same deflator.

Nominal return vs real return

What matters for your purchasing power is the real return: (1 + nominal return) ÷ (1 + inflation) − 1. A 7% return with 3% inflation is about 3.9% in real terms, not 4%. A deposit paying less than inflation loses purchasing power even though the balance grows.

Which inflation rate to use

The European Central Bank targets 2% over the medium term, and euro-area inflation averaged somewhat below 2% between 1999 and 2020. It is not stable: in October 2022 it exceeded 10%. Try several rates to see a range instead of a single number. The rule of 70 gives a quick estimate: at 3% prices double in about 23 years.

Frequently asked questions

How do I calculate the loss of purchasing power?

Divide the amount by (1 + inflation) raised to the number of years. At 3% for 10 years, €10,000 is equivalent to about €7,441 today, a loss of roughly 26%.

What is the real return of an investment?

It is the return after inflation: (1 + nominal return) ÷ (1 + inflation) − 1. It tells you how much more you can actually buy, not how many more euros you have.

Does the calculator use historical inflation?

No. It assumes a constant annual rate that you choose. Real inflation changes every year, so the result is an illustration of the mechanism, not a forecast.

Is the invested return guaranteed?

No. The return is an assumption. Index portfolios have years with losses; a constant rate hides that volatility and does not include costs or taxes.

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