Flat Rate vs Reducing Balance Rate in Personal Loans: Which One Costs More?


Flat interest rates and reducing balance interest rates are the two important approaches for calculating interest on a personal loan. Selecting between flat and reducing interest rates can significantly influence the overall interest cost, so it’s important to understand these options before signing an agreement for a personal loan. 

Flat Interest Rate vs Reducing Balance Interest Rate 

Flat Interest Rate 

Interest is calculated on the original full loan amount, every single month, throughout the entire loan tenure. 

Even after you have repaid half the loan, the interest continues to be charged on the original amount. You essentially pay for money you no longer owe. 

  • Interest amount stays the same every month 
  • Total interest paid is significantly higher 
  • Often used by some NBFCs and short-term lenders 

Reducing Balance Interest Rate 

Interest is calculated only on the outstanding loan balance, which reduces with every EMI payment you make. 

As your principal reduces each month, the interest component of your EMI also reduces. You pay interest only on what you actually still owe. 

  • Interest amount decreases every month 
  • Total interest paid is lower 
  • Used by most banks in India

Comparison: Features at a Glance

Feature Flat Interest Rate Reducing Balance Interest Rate

Interest calculated on 

Full original loan amount 

Remaining outstanding 

balance

Monthly interest 

amount

Stays the same throughout 

Decreases every month

Total interest paid 

Higher 

Lower

Transparency 

Less transparent 

More transparent

Effective cost 

Much higher than the stated rate

Close to stated rate

Common users 

Some NBFCs, short-term lenders

Most banks (SBI, HDFC, 

ICICI, etc.)

Suitable for 

Very short-term, small loans only

Medium to long-term loans

Real Rupee Example: Same Loan, Same Rate, Different Cost 

Flat rate charges interest on what you borrowed. Reducing balance rate charges interest on what you still owe. There is a big difference. This can be understood by following example, in which there is same loan amount, same interest rate, same tenure with a different method of calculating the interest rate. 

Loan Details: 

  • Loan Amount: ₹3,00,000 
  • Interest Rate: 12% per annum 
  • Tenure: 3 years (36 months) 
Parameter Flat Rate @ 12% Reducing Rate @ 12%

Monthly EMI 

~₹11,333 

~₹9,964

Total Amount Paid 

₹4,08,000 

₹3,58,704

Total Interest Paid 

₹1,08,000 

₹58,704

Extra Cost vs Reducing 

₹49,296 more expensive 

Important: A 12% flat rate loan costs you ₹49,296 more than a 12% reducing balance loan on just ₹3 lakh over 3 years. On a larger loan or longer tenure, this gap becomes even wider. 

Understanding interest calculation is just as important as comparing Personal Loan Interest Rates.

Which One Should You Choose? 

The reducing balance rate is the better choice in most of the cases, especially for personal loan more than ₹1 Lakh. It is cheaper, more transparent, and the rate you see is genuinely close to the rate you pay. A flat rate loan might be acceptable for a very small, very short-term loan (say ₹20,000 for 3 months) where the absolute rupee difference is minimal, and convenience outweighs cost.