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About

A nominal return of 8% sounds impressive, but if inflation is running at 5%, your actual wealth is barely growing. This tool calculates the Real Rate of Return, which is the mathematically corrected growth rate of purchasing power. The "Money Illusion" often misleads investors into believing they are richer than they are, while the silent erosion of currency value (inflation) degrades the utility of those future dollars.

Using the Fisher Equation logic, this utility shocks the user into recognizing that preserving capital requires a return strictly greater than the CPI index. It is essential for retirement planning to ensure your "Nest Egg" can actually purchase the goods and services you need in 20 or 30 years.

inflation real return purchasing power cpi economics

Formulas

The approximation rreal rnom - i is often used, but the precise Fisher Equation is:

1 + rreal = 1 + rnom1 + i

Where i is the inflation rate. This accounts for the fact that the interest earned is also subject to inflation.

Reference Data

RegionHigh Inflation EraAvg RatePurchasing Power Loss (10y)
USA (Great Inflation)1970-19807.4%-51%
USA (Recent)2010-20201.7%-16%
UK (Stagflation)1970-198012.6%-70%
Eurozone2000-20102.2%-20%
Global Average1990-20233.8%-31%

Frequently Asked Questions

Simple subtraction (Nominal - Inflation) ignores the cross-term. The precise formula divides the growth factors. As inflation gets higher, the gap between the simple subtraction and the true real rate widens.
This occurs when Inflation > Nominal Return. For example, a bank savings account paying 1% when inflation is 3% has a real return of roughly -2%. You are losing purchasing power every single day, effectively paying the bank to hold your depreciating money.
Yes. The "Real Net Return" subtracts both taxes and inflation. It is the harshest but most honest metric of wealth generation.