Published on Jul 15, 2025Updated on Sept 4, 2026
Your personal loan interest rate calculation directly affects your monthly EMI, total interest payable, and overall repayment amount. In 2026, the rate of interest, or personal loan ROI, offered by lenders in India typically varies based on factors such as your credit score, income, loan amount, tenure, and the lender's policy at the time of application.
Therefore, knowing how to calculate the interest rate on a loan before applying can help you plan repayments, compare lenders, and choose a tenure that keeps borrowing costs manageable.
If you are wondering how to calculate the interest rate per month, it depends on the annual interest rate/ROI and the repayment method. Further, the personal loan EMI formula considers the loan amount, monthly interest rate, and tenure to determine your monthly instalment and the total personal loan interest amount payable.
A personal loan interest rate, also called ROI (Rate of Interest), is the annual percentage a lender charges on the principal amount you borrow. This annual interest rate is broken down into a monthly interest rate for EMI calculation purposes.
The monthly interest rate is calculated by dividing the annual ROI by 12 and then by 100.
For example, SMFG India Credit’s personal loan interest rate starts from 12%* per annum. Then, the monthly interest rate is:
Monthly Interest Rate = 12 ÷ 12 ÷ 100 = 0.01
Key terms to understand:
Personal loan interest is calculated using the reducing-balance method, in which the monthly interest rate is applied to the outstanding principal amount at the start of each month. As you repay each EMI, the interest component of subsequent EMIs goes down.
The standard loan interest calculation formula used across lenders in India is:
EMI = [P × R × (1+R)^N] / [(1+R)^N – 1]
Here, R is the monthly interest rate, calculated by dividing the annual personal loan ROI by 12 and then by 100.
Let’s understand the formula in detail below.
EMI = [P × R × (1+R)^N] / [(1+R)^N – 1]
Where:
This EMI calculation formula gives you the fixed monthly instalment. Since the reducing balance method applies, the interest component in each EMI is different. Early EMIs have a higher interest share; later EMIs repay more principal.
If you are wondering how to calculate interest percentage on a loan, first convert the annual interest rate into a monthly interest rate by dividing it by 12 and then by 100. The annual interest rate is determined by the lender based on several factors, such as your credit score, income, repayment capacity, loan amount, tenure, employment profile, and overall application details. You can then apply the full formula to estimate the EMI and the total interest payable.
Here is how to calculate the interest on a loan using a realistic example:
Loan Details:
Step 1: Know how to calculate the interest rate per month.
R = 12 ÷ 12 ÷ 100 = 0.01
Step 2: Apply the EMI formula
EMI =
[10,00,000 × 0.01 × (1 + 0.01)^60] ÷ [(1 + 0.01)^60 – 1]
EMI ≈ Rs. 22,224
Step 3: Calculate the total repayment amount.
Total repayment = Rs. 22,224× 60 = Rs. 13,34,667
Step 4: Calculate the total interest payable on the personal loan.
Total interest payable = Rs. 13,34,667– Rs. 10,00,000 = Rs. 3,34,667
This means the borrower pays Rs. 3,34,667 as interest over the full tenure on a Rs. 10 lakhs personal loan at 12% per annum for 5 years.
Here’s how to calculate the interest amount on a loan across different loan amounts and tenures using illustrative examples.
|
Loan Amount (Rs.) |
Interest Rate (Per Annum) |
Tenure |
Approx. Monthly EMI (Rs.) |
Total Interest Payable (Rs.) |
Total Repayment Amount (Rs.) |
|
3,00,000 |
12% |
2 years |
14,122 |
38,929 |
3,38,929 |
|
5,00,000 |
12% |
3 years |
16,607 |
97,858 |
5,97,858 |
|
10,00,000 |
12% |
4 years |
26,334 |
2,64,024 |
12,64,024 |
Values are indicative. Actual EMI, interest payable, and total repayment amount may vary based on the interest rate and other terms applicable under the lender's policy at the time of loan application.
Each EMI consists of two parts: the interest component and the principal component. In early EMIs, the interest share is higher because the outstanding principal is large. As you repay, the principal reduces, and so does the interest charged each month. This is the core of the reducing balance method.
If you’re wondering how to calculate personal loan interest for a specific month, you can use Excel's built-in function:
=IPMT(rate, period, nper, pv)
Where:
Example:
Loan: Rs. 5,00,000 at 12% for 60 months
To find the interest component in month 1: =IPMT(12%/12, 1, 60, -500000) ≈ Rs. 5,000
If the monthly EMI is Rs. 11,122, the principal repaid in month 1 is: Rs. 11,122 – Rs. 5,000 = Rs. 6,122
By the final month of the loan tenure, the interest component reduces significantly, while the principal repayment component increases. This is how to find the interest on a loan month by month, and it is exactly what your amortisation schedule shows.
Lenders calculate personal loan interest rates based on several key factors that help assess a borrower’s risk profile and repayment capacity.
Your CIBIL score/credit score is one of the first aspects lenders evaluate. A high CIBIL score (typically 700 or above) signals strong creditworthiness and may qualify you for lower interest rates. While lenders may have different minimum score requirements, a better score often translates into more favourable loan terms.
When lenders assess your loan application, the amount you want to borrow also plays a role in determining the interest rate. If you have a solid repayment history, you’re more likely to be approved for a larger loan at a competitive rate.
The chosen tenure impacts how you calculate personal loan interest over time. Shorter tenures generally mean higher EMIs but lower overall interest paid. On the other hand, longer tenures reduce your monthly burden but increase the total interest outgo over the loan’s duration.
|
Method |
Best For |
Advantages |
Considerations |
|
Manual formula |
Understanding the calculation |
Transparent, educational |
Time-consuming, error-prone |
|
EMI/Loan interest calculator |
Quick financial planning |
Instant, accurate, and easy to compare different loan scenarios |
Results are indicative |
|
Excel IPMT function |
Monthly interest breakdown |
Detailed, month-by-month |
Requires basic Excel knowledge |
For most borrowers, using a personal loan EMI calculator online is the quickest way to estimate the monthly EMI and total interest payable across different loan scenarios. You can adjust the loan amount, tenure, and interest rate in seconds to find the combination that works best for your budget.
An amortisation schedule is a month-by-month loan repayment schedule that shows exactly how each EMI is split between interest and principal. It also tracks the closing outstanding principal amount after each payment.
Here is a sample amortisation schedule for a Rs. 5,00,000 personal loan at 12% per annum, showing the first five months of a 60-month tenure (EMI ≈ Rs. 11,122):
|
Month |
Opening Principal Outstanding (Rs.) |
Interest Paid (Rs.) |
Principal Repaid (Rs.) |
Resulting Principal Outstanding (Rs.) |
|
1 |
5,00,000 |
5,000 |
6,122 |
4,93,878 |
|
2 |
4,93,878 |
4,939 |
6,183 |
4,87,695 |
|
3 |
4,87,695 |
4,877 |
6,245 |
4,81,450 |
|
4 |
4,81,450 |
4,815 |
6,308 |
4,75,142 |
|
5 |
4,75,142 |
4,751 |
6,371 |
4,68,772 |
The amortisation schedule clearly shows how the interest component gradually decreases while the principal repayment component increases with each EMI.
Knowing how to calculate personal loan interest can help you make more informed borrowing decisions. Whether you use the EMI formula manually or an online calculator, understanding the monthly interest rate calculation, total interest payable, and the amortisation schedule gives you a clearer picture of your repayment obligations.
Before applying, compare personal loan interest rates, maintain a healthy CIBIL score, and choose a tenure that balances your monthly EMI comfort with the total interest payable over the loan's life.
Use SMFG India Credit's personal loan EMI calculator to estimate your repayments and check your eligibility before applying for financing of up to Rs. 10 Lakhs* at competitive interest rates. For more information or assistance, feel free to contact us.
* Please note that this article is for your knowledge only. Loans are disbursed at the sole discretion of SMFG India Credit. Final approval, loan terms, disbursal process, foreclosure charges and foreclosure process will be subject to SMFG India Credit's policy at the time of loan application. If you wish to know more about our products and services, please contact us
The annual rate of interest (ROI) is determined by the lender based on factors such as your credit score, income, loan amount, tenure, and overall application profile. If you wish to know how to calculate the interest rate per month, divide the annual ROI by 12 and then by 100. You can then use an EMI calculator to estimate the total interest payable over the loan tenure.
To secure a favourable personal loan interest rate, maintain a high credit score (preferably 700 or above), ensure a stable source of income, keep your debt-to-income ratio below 30%, and compare offers from multiple lenders. Choosing a shorter loan tenure can also help reduce the interest rate.
The lowest applicable interest rate depends on several factors, such as your eligibility, creditworthiness, repayment capacity, and lender policies at the time of loan application. SMFG India Credit offers competitive personal loan interest rates starting from 12%* per annum.
The RBI does not set personal loan interest rates directly. Instead, it regulates the repo rate, which influences how financial institutions set their lending rates for personal loans.
The formula for EMI is:
EMI = P * r * (1+r)^n/ ((1+r)^n-1)
Where,
P = principal
r = monthly interest rate
n = loan tenure
The interest rate is calculated on a monthly basis. If we consider annual ROI to be 12%, the calculation will be as follows:
R - 12/12/100 = 0.01.
Let us continue with the above example. Consider the loan amount to be Rs. 10,00,000 with a tenure of 5 years/60 months and an annual ROI of 12% (monthly = 0.01). Using the formula EMI = P * r * (1+r)^n/ ((1+r)^n-1), the EMI is calculated to be Rs. 22,244. The total amount payable is Rs. 13,34,667.
The interest amount will be: Rs. 13,34,667- Rs. 10,00,000 = Rs. 3,34,667.
The credit score's impact on interest rates is considerable. A score of 700 and above shows strong creditworthiness. It will increase your chances of loan approval with a lower interest rate, provided you fulfil other eligibility criteria. Paying credit card dues or loans on time, not using too much credit, and not applying for too much credit at once are some ways you can improve your credit score.
A guarantor is only required if the applicant:
You can apply for a personal loan at SMFG India Credit without a guarantor as long as you have a credit score of at least 700 and a stable income source to repay without difficulty. If you have trouble with either, consider a co-applicant with a strong credit history and income source to avoid a guarantor. SMFG India Credit provides personal joint loans for family members.
Many factors affect the personal loan process at SMFG India Credit. Some of the most important are:
To calculate an unknown interest rate, you need variables such as the loan amount, EMI, loan tenure, and total repayment amount. You can then use a financial calculator or Excel's RATE function to estimate the annual interest rate.
To calculate the interest percentage mathematically, you need the loan amount, EMI, repayment tenure, and total repayment amount. You can then use an online financial calculator or Excel's RATE function to estimate the annual interest rate. Note that the actual final interest rate offered will be determined by the lender based on your application profile. Contact your lender for the exact applicable rate or any clarification.
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