Real Return: Adjusting for Inflation
You invested for 10 years and earned a 30% return. But if prices also rose 30% over the same period, in real terms you stayed in place.
Nominal Return vs. Real Return
The nominal return is the return we usually talk about. If you invest about $740 and it becomes about $792, that's 7%.
The real return is the return with inflation removed. If prices rose 3% over the same period, the real return is about 4% (precisely (1.07/1.03)-1 = 3.88%).
Thanks to inflation, what your about $792 can buy increased by 4% more, not 7% more. Your real purchasing power rose 4%.
How Inflation Eats Into Purchasing Power
Historical inflation levels (based on Korea's Consumer Price Index): 2000s: 2.5-3.5% per year 2010s: 1-2% per year 2021-2023: 3-6% per year (a surge after COVID-19)
If 3% annual inflation persists: Prices after 10 years: 1.34x current -> today's 1 million KRW = about 1.34 million KRW needed after 10 years Prices after 20 years: 1.81x current Prices after 30 years: 2.43x current
If 3% annual inflation persists for 30 years, the purchasing power of 100 million KRW today shrinks to about 41 million KRW in 30 years. If you had held only cash without investing, 59% of your purchasing power would have vanished.
The Rule of 72 in reverse: at 3% inflation, the value of money halves after 72/3 = 24 years.
Calculating the Real Return
The exact real-return formula: Real return = (1 + nominal return) / (1 + inflation rate) - 1
A convenient approximation: Real return is approximately nominal return - inflation rate
Example: nominal return 7%, inflation 3% Exact real return: (1.07/1.03) - 1 = 3.88% Approximation: 7% - 3% = 4%
The difference between the two methods is negligible when returns are low, but it grows when both the return and inflation are high.
Major Korean Assets Through the Lens of Real Return
When Korea's deposit rate is 3% per year and inflation is also 3%, the real return is close to 0%. You preserved your principal, but your purchasing power stayed in place.
The U.S. S&P 500's historical real return (nominal about 10% minus U.S. inflation of about 3%) is around 7% per year. An increase in real purchasing power that outpaces inflation is one of the core reasons for long-term stock investing.
Frequently Asked Questions
Q. Is a 5% return better than 3% inflation as an investment?
In real-return terms, it is about +2%. Not bad, but not outstanding either. Once you factor in taxes (dividend tax, capital gains tax, etc.), the real after-tax return can drop to the 0-1% range. In long-term investing, it is important to aim for a real return that at least outpaces inflation.
Q. How do you calculate the real return?
The exact formula: real return = (1 + nominal return) / (1 + inflation rate) - 1. Example: with a nominal return of 8% and inflation of 3%, (1.08/1.03)-1 = 4.85% is the real return. You can approximate it as 8%-3%=5%, but the error grows as inflation rises.
📋 Results are based on historical data; past returns do not guarantee future returns.
📋 This service is provided for educational purposes to help you understand investing, not as investment advice.