Flat Interest Rate and Effective Interest Rate Calculator

A flat interest rate, commonly used for personal and car loans, is a fixed rate applied to the initial loan amount throughout the loan's duration.

For instance, if you borrowed RM100,000 at a flat interest rate of 4% per annum over 10 years, you'd be charged 4% interest annually on the original loan amount, regardless of how much of the loan you've already repaid. So, even if you've repaid RM99,000, the 4% interest is still calculated based on the initial RM100,000 loan. Consequently, your total interest over the 10-year term would be RM40,000 (RM100,000 * 4% * 10). This means you're paying interest on the original loan amount, not the remaining loan balance.

The effective interest rate, often referred to as the reducing balance method, is a way to calculate the interest on a loan where the interest amount decreases as you pay off the principal. With each payment, you are reducing the principal amount on which the interest is calculated, thus lowering the total interest you pay over the life of the loan.

For instance, if you have a personal loan of RM100,000 with an effective interest rate of 4% per annum for a duration of 10 years, the 4% interest is calculated on the outstanding balance of the loan after each payment, not the initial loan amount. This means that with each installment, you pay less in interest because you're paying interest on a decreasing balance.

By the end of the 10 years, you would have paid RM 21,494 in interest, which is significantly less than what you would have paid if a flat interest rate was applied. The effective interest rate thus reflects the true annual cost of the loan, making it a more accurate tool for comparing different loan options.

Here are some key differences between flat and effective interest rates:

Use the Flat to Effective Interest Rate Calculator to understand the actual monthly interest payment to your lender. If you're comparing a flat interest rate with an effective one and aren't sure about the difference, you might be inclined to choose the flat rate, as it's often advertised at a seemingly lower percentage.

However, over a longer period, a flat interest rate could cost significantly more than an effective one. This knowledge can help you save a substantial amount of money in the long run.