Using Real Interest Rate to Calculate What You Own

What is the Real Interest Rate?

The real interest rate is the nominal interest rate adjusted for inflation. It represents the true purchasing power of your money over time. Unlike nominal interest rates, which can be misleading due to inflation, the real interest rate gives you a clearer picture of your investment's actual return.

For example, if the nominal interest rate is 5% and inflation is 2%, the real interest rate would be 3%. This means your money is actually growing at 3% in terms of purchasing power.

How to Calculate What You Own Using Real Interest Rate

To calculate the value of your assets using the real interest rate, you need to consider both the nominal value and the inflation rate. The formula for the real value of your assets is:

Where:

• Nominal Value is the current market value of your assets
• Inflation Rate is the annual rate of inflation
• Time Period is the number of years you've owned the assets

This calculation helps you determine the true value of your assets after accounting for inflation. It's particularly useful for comparing the value of assets over different time periods.

The Formula Explained

The formula for calculating the real value of your assets is derived from the concept of present value in finance. By dividing the nominal value by the inflation-adjusted factor, you account for the erosion of purchasing power due to inflation.

The formula assumes that inflation is constant over the time period. In reality, inflation rates can vary, but this provides a reasonable approximation for most practical purposes.

Worked Example

Let's say you own a house worth $300,000 and you've owned it for 5 years. The annual inflation rate is 2%. To calculate the real value of your house:

This means your house has a real value of approximately $271,500 after accounting for inflation over 5 years. This is lower than the nominal value because inflation has reduced the purchasing power of your money.