Interest Rates Explained: Nominal, Real, and Effective

Reviewed by Erika RasureFact checked by Vikki VelasquezReviewed by Erika RasureFact checked by Vikki Velasquez

What Are the Different Interest Rates?

The term “interest rate” is one of the most commonly used phrases in the fixed-income investment lexicon. The different types of interest rates, including real, nominal, effective, and annual, are distinguished by key economic factors, that can help individuals become smarter consumers and shrewder investors.

Key Takeaways

• Different types of interest rates, such as real, nominal, effective, and annual, are set apart by critical economic factors.
• The nominal interest rate, or coupon rate, is the actual price borrowers pay lenders, without accounting for any other economic factors.
• The real interest rate accounts for inflation, giving a more precise reading of a borrower’s buying power after the position has been redeemed.
• The effective interest rate includes the impact of compounding, in which a bond might pay interest annually but compounds semiannually, increasing the overall return.

Nominal Interest Rate 

The nominal interest rate is the stated interest rate of a bond or loan, which signifies the actual monetary price borrowers pay lenders to use their money. If the nominal rate on a loan is 5%, borrowers can expect to pay $5 of interest for every $100 loaned to them. This is often referred to as the coupon rate because it was traditionally stamped on the coupons redeemed by bondholders.

Nominal interest rates refer to the interest rates that are unadjusted for inflation. In other words, it is the stated or quoted interest rate on a loan or investment without taking into account the impact of inflation or deflation over time. Nominal interest rates are typically expressed on an annual basis, such as 5%, 7%, or 10%, and they represent the percentage of the loan amount or investment principal that must be paid as interest during a specific period.

Important

Real interest rates can be negative. Even if the nominal rate is positive, inflation can erode purchasing power so far that money loses its value when held onto.

Real Interest Rate

The real interest rate is so named, because unlike the nominal rate, it factors inflation into the equation, to give investors a more accurate measure of their buying power, after they redeem their positions. If an annually compounding bond lists a 6% nominal yield and the inflation rate is 4%, then the real rate of interest is actually only 2%.

Real interest rates are crucial for making informed financial decisions, especially in the context of investments and loans. When assessing investment opportunities or evaluating the cost of borrowing, it is essential to consider the real interest rate to understand the true economic impact and how inflation may affect the return on investment or the actual cost of borrowing.

Effective Interest Rate

Investors and borrowers should also be aware of the effective interest rate, which takes the concept of compounding into account. For example, if a bond pays 6% annually and compounds semiannually, an investor who places $1,000 in this bond will receive $30 of interest payments after the first six months ($1,000 x .03), and $30.90 of interest after the next six months ($1,030 x .03). In total, this investor receives $60.90 for the year. In this scenario, while the nominal rate is 6%, the effective rate is 6.09%.

Mathematically speaking, the difference between the nominal and effective rates increases with the number of compounding periods within a specific time period.

Applications of Nominal, Real, and Effective Rates

Many financial products state the interest rate as a nominal rate. For example, financial institutions often advertise their loan or deposit products using nominal interest rates. This allows customers to quickly understand the rate they would be receiving or paying without the need for adjustments. In addition, many financial contracts such as mortgages, personal loans, and credit cards, specify the nominal interest rate that will be applied to the principal amount.

Real rates are usually more used when analyzing investment decisions. When evaluating investment opportunities (particularly in fixed-income assets like bonds or savings accounts), real interest rates are considered to determine the actual purchasing power of the investment return after accounting for inflation. When planning for long-term financial goals like retirement, real interest rates are more relevant as they incorporate eroding purchasing power. In addition, assessing international investments may call for real rates as different regions may be impacted by differing macroeconomic policies.

Note that effective interest rates are not appealing to borrowers as it reflects higher costs. However, effective interest rates are appealing to savers as they will earn more with more compounding periods.

Nominal, Real, and Effective Rate Regulation

There are many financial policies enacted to protect consumers, many of which revolve around the concept of transparency and equity on interest rates. Many countries have regulations that mandate financial institutions to provide clear and transparent information about interest rates to consumers. This includes disclosing both nominal and effective interest rates, as well as any fees or charges associated with the loan or investment that may or may not be associated to these rates.

There are many specific acts and laws around the world. In the United States, the Truth in Lending Act requires lenders to disclose the APR to borrowers. The APR represents the effective interest rate and includes not only the nominal rate but also any additional fees or costs involved in the loan.

In the United Kingdom, the Consumer Credit Act is a law that regulates consumer credit agreements and protects borrowers. It applies to various credit arrangements, including loans, credit cards, and hire-purchase agreements. The Act requires lenders to provide clear and transparent information to consumers about the cost of credit, including the total amount repayable, the interest rate, and any fees or charges. It sets rules on credit advertising and marketing practices, ensuring that consumers are not misled or subjected to unfair practices.

Special Considerations

Negative Interest Rates

It’s feasible for real interest rates to be in negative territory if the inflation rate exceeds the nominal rate of an investment. For example, a bond with a 3% nominal rate will have a real interest rate of -1%, if the inflation rate is 4%. A comparison of real and nominal interest rates can be calculated using this equation:

​RR=Nominal Interest Rate − Inflation Ratewhere:RR = Real Rate of Return​

Several economic stipulations can be derived from this formula, which lenders, borrowers, and investors may utilize to cultivate more informed financial decisions.

• Typically, when the inflation rates are negative (deflationary), real rates exceed nominal rights. But the opposite is true when inflation rates are positive.
• One theory believes the inflation rate moves in tandem with nominal interest rates over time, meaning that real interest rates become stable over long time periods. Therefore, investors with longer time horizons may be able to more accurately assess their investment returns on an inflation-adjusted basis.

TIPS and Other Alternatives

Investors who seek protection from inflation in the fixed-income arena may elect to consider Treasury Inflation-Protected Securities (TIPS), which pay interest rates that are indexed to inflation. Therefore, investors can target a specific real rate of return (which factors in inflation) as opposed to chasing nominal returns which may actually have eroding purchasing power. Alternatively, mutual funds investing in bonds, mortgages, and senior secured loans that pay floating interest rates, also periodically adjust with current rates.

Example of Nominal, Real, and Effective Rates

Let’s consider a real-world example involving a car loan to illustrate real, nominal, and effective interest rates. You want to purchase a car and decide to take out a car loan from a bank. The bank offers you the following terms:

• Nominal Interest Rate: 6% per year
• Loan Term: 5 years (60 months)
• Loan Compounding Frequency: Monthly
• Inflation Rate: 2%

The nominal rate is the stated annual interest rate, which, in this case, is 6%. However, this rate is expressed on an annual basis and does not take into account the effect of compounding over the course of the loan. Note that when you sign your auto loan paperwork, the nominal rate is usually stated.

The effective rate accounts for the impact of compounding. In this example, the compounding frequency is monthly. To calculate the effective interest rate, we use the formula:

Effective Interest Rate = (1 + (Nominal Interest Rate / Number of Compounding Periods))^(Number of Compounding Periods) – 1

In this case, the formula is: Effective Interest Rate = (1 + (6% / 12))^(12) – 1 ≈ 6.17%. This rate reflects the true cost of borrowing on an annual basis, accounting for monthly compounding.

To calculate the real rate, we need to consider the inflation rate. The real interest rate is (6% nominal rate less 2% inflation) 4%.

In this example, the main takeaway is to understand how one rate may be substantially different from other. These three rates, all accurate and related to the same loan, range from 4% to 6.17%. Over the life of the auto loan, even one to two percentage points may amount to hundreds of dollars of extra charges; this is compounded for larger loans such as mortgages.

What Factors Influence Changes in Nominal Interest Rates?

Nominal interest rates can be influenced by various economic factors, including central bank policies, inflation expectations, credit demand and supply, overall economic growth, and market conditions. When the economy is growing and demand for credit is high, nominal interest rates may rise, and vice versa during economic downturns.

Why Do Effective Interest Rates Matter for Borrowers?

Effective interest rates matter for borrowers because they reflect the true cost of borrowing, including compounding. Borrowers can use effective rates to compare loan offers accurately and understand the total amount they will repay over the loan term.

How Do Central Banks Use Nominal and Real Interest Rates in Monetary Policy?

Central banks set nominal interest rates as part of their monetary policy to influence economic activity. They use real interest rates to gauge the stance of their policy after considering inflation, helping to ensure stable economic growth and maintain price stability.

How Do Real Interest Rates Impact Retirement Planning?

Real interest rates play a significant role in retirement planning as they affect the growth of savings and investments over time. Positive real interest rates can help preserve purchasing power during retirement, ensuring that investments grow at a rate higher than inflation. However, negative real rates could lead to a decline in the real value of savings and investments, necessitating careful planning to offset inflationary effects.

The Bottom Line

When it comes to a bond’s interest rates, shrew investors know to look beyond nominal or coupon rates when considering their overall investment objectives. In addition, be mindful of taking out loans and knowing your effective interest rate. A qualified financial advisor can help investors navigate interest rates that keep up with inflation as well as unearth the true cost of debt.

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