How Does a Reducing Balance Loan Work for a Rs. 50 Lakh Home Loan?

Q: I took a Rs. 50,00,000 home loan for 20 years at 8% interest, and the bank says my EMI is about Rs. 41,800.

They also keep telling me it’s a ‘reducing balance loan,’ but I don’t really get that.

In the first month, they say almost Rs. 33,000 out of my EMI is just interest and only around Rs. 8,800 goes toward the principal. Later, the interest part will reduce and the principal part will increase.

But why isn’t the interest simply 8% of the Rs. 50,00,000 I borrowed?

And if I prepay, say Rs. 5,00,000 after a few years, will that actually save me a lot of interest?

Basically, how is this reducing balance loan interest really being calculated?

Answer:

When you took your Rs. 50,00,000 home loan at 8% interest for 20 years, the bank told you it’s a “reducing balance loan.” That term sounds fancy, but it’s actually pretty straightforward.

Unlike a fixed interest loan (where the interest is calculated on the full loan amount for the entire term), a reducing balance loan calculates interest only on the outstanding loan amount each month.

As you pay your EMI, Rs. 41,800 in your case, part of it reduces the principal, so the next month’s interest is calculated on a slightly smaller amount.

This is why the interest portion of your EMI starts high (Rs. 33,000) and gradually decreases, while the principal portion increases over time.

Quick Analogy

Let’s dive into a more detailed analogy to really drive home how a reducing balance loan works compared to a fixed interest loan.

Imagine you borrow Rs. 1,000 from a friend to buy a phone. You’ll pay it back over 10 months with 10% annual interest.

Your friend offers two ways to calculate interest:

• Fixed Interest: You pay interest on the full Rs. 1,000 every month, even as you pay back the loan. So, the interest is always Rs. 1,000 × 10% ÷ 12 = Rs. 8.33 per month.
• Reducing Balance: You only pay interest on what you still owe.
  • In month one, interest is Rs. 8.33 (10% of Rs. 1,000). If you pay Rs. 100, Rs. 8.33 covers interest, and Rs. 91.67 reduces the loan to Rs. 908.33.
  • Second month, interest is lower (10% of Rs. 908.33 ≈ Rs. 7.57), so more of your payment goes to the principal.

This way you can see, it saves you money as interest shrinks each month.

Your home loan is like this reducing balance deal. Each EMI reduces what you owe, so the interest (like the Rs. 33,000 in your first EMI) gets smaller over time, unlike a fixed interest loan where it stays the same.

Why Isn’t the Interest Just 8% of Rs. 50,00,000?

You’re probably thinking: “8% of Rs. 50,00,000 is Rs. 4,00,000 per year, so shouldn’t my monthly interest be Rs. 4,00,000 ÷ 12 = Rs. 33,333?” That’s a logical assumption, but it’s not how reducing balance loans work. Let’s dig into the math to see why your first month’s interest is around Rs. 33,000.

Your EMI of Rs. 41,800 is calculated using a formula that ensures the loan (principal + interest) is fully paid off in 20 years (240 months). The formula (often computed in Excel using the PMT function) balances the principal repayment and interest so that each EMI is the same, but the split between interest and principal changes over time.

In the first month, your outstanding loan is the full Rs. 50,00,000. The interest for that month is:Interest = (Outstanding Principal × Annual Interest Rate) ÷ 12= (50,00,000 × 8%) ÷ 12 = Rs. 33,333

This is close to the Rs. 33,000 the bank mentioned. The slight difference might be due to rounding or specific terms in your loan agreement. So, your EMI of Rs. 41,800 breaks down as:

• Interest: ~Rs. 33,000
• Principal: Rs. 41,800 − Rs. 33,000 = ~Rs. 8,800

After paying this EMI, your outstanding loan drops to Rs. 50,00,000 − Rs. 8,800 = Rs. 49,91,200. In the second month, the interest is calculated on this new, slightly lower amount:

Interest = (49,91,200 × 8%) ÷ 12 ≈ Rs. 33,274

Notice how the interest is a bit less because the principal is lower. This cycle continues, with the interest portion shrinking and the principal portion growing each month. That’s the magic of a reducing balance loan—it saves you money over time compared to a fixed interest loan, where the interest stays constant.

Visualizing the Difference

Fixed vs. Reducing BalanceTo make this clearer, let’s look at a graph I used in an old blog post. It compares the interest payment schedules for a fixed interest loan versus a reducing balance loan.

This graph shows how, in a reducing balance loan (the blue bars and line), the interest you pay each month decreases as the loan balance drops.

In contrast, a fixed interest loan (the orange line) charges the same interest every month, no matter how much you’ve paid off.

For your home loan, you’re on the reducing balance path, which is why the bank said the interest portion will shrink over time.

Will Prepaying Rs. 5,00,000 Save You Interest?

Now, let’s take your question about prepaying Rs. 5,00,000.

The short answer? Yes, it can save you a lot of interest, but let’s see how.

When you prepay Rs. 5,00,000, you reduce the outstanding principal. Since interest is calculated on the remaining balance, a lower principal means less interest each month.

There are two ways banks typically handle prepayments:

1. Reduce the EMI, keep the tenure the same: Your monthly EMI drops, but you still pay for 20 years (read about it here).
2. Reduce the tenure, keep the EMI the same: You pay the same Rs. 41,822 monthly but clear the loan faster (before 20 years).

Most borrowers prefer the second option because it saves more interest and shortens the loan period.

Let’s estimate the impact using a simplified example.

Suppose you prepay Rs. 5,00,000 after 5 years (in the 61st month). By then, your outstanding principal might be around Rs. 43,76,279.

Prepaying Rs. 5,00,000 reduces the principal to Rs. 38,76,279 (instead of Rs. 43,76,279).

If you keep the EMI at Rs. 41,822, the loan will be paid off faster, by the end of the 17th years.

This will also save you about Rs. 14,70,000 on interest payments.

A rule of thumb, the earlier one makes the payment, more will be the potential savings. In this case, we have assumed a loan prepayment of Rs. 500,000 in the 61st month. Had this prepayment been made in the 37th month (end of the third year), the savings would have been in the tune of Rs. 16,95,000.

Why Reducing Balance Loans Are Borrower-Friendly?

Reducing balance loans, like your home or car loan, are designed to be fairer to borrowers.

Every time you pay an EMI, you take a small bit away from the principal loan balance. This eventually lowers the interest you pay in the next month.

This is why your bank’s Rs. 33,000 interest in the first month will gradually drop, and more of your EMI will go toward paying off the actual loan.

Compare this to a fixed interest loan, where the interest is calculated on the original Rs. 50,00,000 for the entire term.

Total Interest Paid (Reducing Balance) in 20 Years	Total Interest Paid (Fixed) in 20 Years
50,37,281	80,00,000

Conclusion

I hope this clears up the confusion about your reducing balance loan and why the interest isn’t just a flat 8% of Rs. 50,00,000.

The reducing balance method saves you money over time by recalculating interest on a smaller principal each month.

And yes, prepaying Rs. 5,00,000 will definitely save you interest, potentially about Rs.14,70,000 if you do it by the end of the fifth year itself.

If you want to play around with the numbers yourself, try the below online EMI calculator.

Reducing Balance Loan Calculator (Online)

Reducing Balance Loan Calculator (Excel)