What is Interest? Know Types and Factors of Interest Rates

Suppose you're planning to buy a car, but you need a loan to afford it. You head to the bank and they agree to lend you the money. However, they mention something called "interest." You might wonder,what is interest? It’s the extra money the bank charges for lending you the amount you need. You can consider it a fee you pay over time for using the bank's money.Without interest, the bank wouldn't make a profit from the loan.In this blog, you will explore what is interest, how it works, and how it affects your loans and savings.

• Interest is the cost of borrowing money, charged as a percentage of the loan amount by lenders.
• There are two main types of interest rates: simple interest and compound interest, each affecting loans differently.
• Simple interest is calculated only on the principal amount, while compound interest is calculated on both the principal and accumulated interest.
• Interest rates work differently for borrowing and savinghigher rates increase borrowing costs but boost savings returns.
• Multiple factors affect interest rates, including your credit score, loan amount, loan tenure, and economic conditions.

Interest is the amount a lender or a financial institution charges a borrower. It is calculated as a percentage of the principal amount loaned. This percentage, known as the interest rate, is expressed on an annual basis and is called the annual percentage rate (APR).Interest can be seen as a fee for the use of money or assets. These assets can include cash, vehicles, property or consumer goods. Higher interest rates make borrowing more expensive, as the cost to repay the borrowed money increases. Most lending or borrowing situations, whether for buying a house, funding a business or paying for college, involve interest rates.Interest rates don’t just apply to loans; they also work in reverse when it comes to savings accounts or certificates of deposit. In those cases, a bank or financial institution pays the account holder a percentage of the funds deposited, known as the annual percentage yield (APY), which is essentially interest earned on these deposits. Types of Interest When you take out a loan, two main types of interest are applied: simple interest and compound interes t.

Simple interest is calculated on the principal amount only. This means the interest does not accumulate over time. The formula for simple interest is:Simple Interest (SI) = Principal (P) × Rate (R) × Time (T)
For example, if you borrow ₹1,00,000 at an interest rate of 5% for 3 years, the simple interest will be:₹1,00,000 × 0.05 × 3 = ₹15,000So, the total interest amount you will pay after 3 years is ₹15,000. In this case, your total repayment amount (principal + interest) would be ₹1,15,000. The interest remains the same each year and there is no compounding involved.

Compound interest is calculated on both the principal and the accumulated interest from previous periods. The interest builds up, meaning you pay or earn interest on interest. The formula for compound interest is:Compound Interest (CI) = P × (1 + R/n)^(n×t) - PFor example, if you invest ₹1,00,000 at an interest rate of 5% for 3 years, compounded annually, the interest would be:₹1,00,000 × (1 + 0.05)^3 - ₹1,00,000 = ₹1,00,000 × 1.157625 - ₹1,00,000 = ₹15,762.50Here, the total interest you pay or earn is ₹15,762.50. Unlike simple interest, compound interest increases with time because it considers the interest accumulated from previous years.Thus simple interest remains constant over time, while compound interest grows over time and is more beneficial in long-term investments or loans. If you're borrowing, compound interest may cost you more, but if you're saving, it can help your investments grow faster.

Here’s a comparison of Simple Interest and Compound Interest based on five key parameters

Interest rates impact nearly every financial decision you make. If you're borrowing money to fund a project or saving to reach your goals, the rate of interest determines how much extra you'll pay or earn.Here are the two scenarios: the impact of interest rates when borrowing money and how they affect your savings.

Impact of Interest Rates While Borrowing

When borrowing money, interest rates define the cost of the loan. Essentially, it's the extra amount you pay the lender in return for using their money. Higher interest rates make borrowing more expensive, while lower rates reduce the overall cost. For example In case you borrow ₹1,00,000 at an interest rate of 10% for 5 years, it means you’ll pay ₹10,000 in interest annually, totalling ₹50,000 in interest amount by the end of the loan term. So, you’ll repay ₹1,50,000 in total (the principal plus interest).Now, if the interest rate were 5%, your interest payment would drop to ₹25,000 for the same period, which makes your total repayment ₹1,25,000. This shows how a lower interest rate can significantly reduce the cost of borrowing and help you save more in the long run.

Impact of Interest Rates While Saving

On the other hand, when you’re saving money, higher interest rates benefit you by growing your savings faster. Banks pay interest on your deposits, and the higher the rate, the more your money earns over time. Interest is compounded, meaning you earn interest not only on the principal amount but also on the interest previously earned. For instance If you deposit ₹1,00,000 in a savings account with a 5% interest rate, compounded annually, you’ll have ₹1,05,000 after one year. Over time, this compounded interest builds up. If the interest rate were only 2%, your balance would grow to ₹1,02,000 after a year, showing how lower rates slow the growth of your savings.

Listed below are five key factors that affect the interest rate on a loan:

• Credit Score

Your credit score is one of the most important factors determining your loan interest rate. Lenders in India, such as banks and NBFCs (non-banking financial corporations), assess your creditworthiness based on your credit score.
A higher score indicates that you’re a low-risk borrower, which makes you eligible for lower interest rates. For example, someone with a credit score of 750 or above may get a personal loan at 11%, while someone with a score below 650 may be charged 15% or higher.

• Loan Amount and Tenure

The loan amount and tenure also impact the interest rate. Higher loans may come with slightly lower interest rates because lenders view them as more profitable, while smaller loans may have higher rates. Similarly, a longer loan tenure generally means a higher interest rate due to the extended risk for the lender.For example, a home loan for ₹50 lakhs over 20 years may have a lower interest rate compared to a 5-year tenure loan of ₹10 lakhs.

• Type of Loan

The nature of the loanwhether it's secured or unsecuredcan also affect the interest rate. Secured loans like home loans and car loans tend to have lower interest rates because they are backed by collateral. Unsecured loans, such as personal loans, have higher interest rates because they pose a higher risk to the lender.For instance, a personal loan in India might come with an interest rate of 14%, while a secured home loan may offer rates as low as 7%.

• Market Conditions and RBI Policy

The Reserve Bank of India (RBI) periodically adjusts its repo rate, which influences the interest rates banks offer. When the RBI raises the repo rate, it becomes more expensive for banks to borrow money, which in turn increases the interest rates on loans. Conversely, when the repo rate is lowered, banks may offer lower loan interest rates.

• Income Stability and Job Profile

Lenders prefer borrowers with a stable income and a good job profile. It reduces the risk of default. Salaried professionals, particularly those working for government or large private companies, are often offered better interest rates than self-employed individuals or those with irregular income sources. Also Read: How Much Personal Loan Can I Get on My Salary?

Whether you're taking out a personal loan, car loan, or unsecured loan, interest is a key factor that accompanies any borrowing decision. Understanding what is interest the cost of borrowing moneycan help you make financial decisions wisely. Generally, there are two types of interest: simple interest and compound interest and choosing the right one depends on your financial goals and the terms offered by your lender.Before committing to any loan, it's essential to evaluate factors such as your credit score, loan term and interest rate. These factors directly impact your repayments and the overall cost of the loan. It’s equally important to understand the lender's terms and conditions, as the interest rate often comes with obligations like specific repayment schedules or penalties.