How to Calculate Interest And Principal Amount in EMI?

EMI (Equated Monthly Installment) is a fixed amount you pay every month to repay your loan. It has two parts: interest and principal. The principal is the original loan amount you borrowed.The interest is the fee charged by the lender for giving you the loan. At the beginning of the loan term, a bigger share of the EMI goes towards interest. As you keep paying, the interest part reduces, and more goes into repaying the principal. Knowing this helps you understand how your loan is reducing over time.
This blog explains how one can calculate the interest and principal amount of EMI.
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ToggleWhat is an EMI?
The full form of EMI is Equated Monthly Instalments. It is called “equated” since this amount is equally distributed for the entire loan term. This is the fixed monthly amount that the borrower must repay towards their loan. The EMI amount consists of part of the principal amount and the interest amount. Typically, the EMI remains constant throughout the loan tenure. In some cases, it may change if there is a revised interest rate or repayment term.
Understanding Principal Amount and Interest Components
The EMI amount consists of the principal amount and interest amount:
- Principal Amount: It is the initial loan amount that is offered to the borrower. This amount forms the base on which interest is calculated
- Interest Components: It is the cost of borrowing that the borrower must pay each month. It is the percentage of the outstanding loan amount charged by the lender for the loan. For instance, the interest rate of 8% per annum means that for every ₹1,000 you borrow, you will need to pay an additional ₹80 as interest each year until the loan is repaid.
Also Read: What is Personal Loan Repayment and Types of Loan Repayment Methods?
How Personal Loan EMI Interest is Calculated: Formula for Calculate EMI
The EMI formula can be calculated considering the principal amount, interest rate, and loan tenure
Formula: EMI = [P × R × (1+R)^N] / [(1+R)^N-1]
P: Principal loan amount
R: Monthly interest rate
N: Total number of months (loan tenure)
Understanding EMI calculation is important to manage loan repayments and manage your finances effectively.
Step-by-Step Guide to Calculate Principal and Interest
Here is our guide to calculate the principal and interest components for each EMI:
1. Gather the Loan Details
- Loan Amount (P): The total amount borrowed.
- Annual Interest Rate (R): The percentage charged as interest per year.
- Loan Tenure (N): Total repayment period in months.
- EMI: Pre-calculated monthly installment.
2. Calculate Monthly Interest Rate
Divide the annual interest rate by 12 and convert it to a decimal:
Monthly Interest Rate (r) = [Annual Interest Rate] / [12 *100]
3. Calculate Interest for the Month
Once the monthly interest is calculated, you need to subtract the monthly interest rate from the outstanding amount.
[Interest] = [Outstanding Principal] * [Monthly Interest Rate]
4. Calculate Principal Repayment for the Month
After you get the principal repayment for the month,
Principal = EMI – Interest
5. Update the Outstanding Principal
[New Outstanding Principal] = [Previous Principal] – [Principal Repaid]
EMI Calculation Example
EMI=P * R *(1+R)^(N)/[(1+R)^(N)-1])
Where,
P: is the principal amount
N: is the loan tenure in months
R: is the monthly interest rate
Let us consider,
- Principal (P): ₹5,00,000
- Loan Tenure (N): 2 years (24 months)
- Annual Interest Rate: 12%
- Monthly Interest Rate (R): (12%)/12=1%=0.011
EMI= [ 5,00,000 * 0.01 * (1+0.01)^24] / [(1+0.01)^24−1]
Calculating step-by-step:
- (1+R)^N= (1+0.01)^24 = (1+0.01)^(24) = 1.2682
- Numerator: 5,00,000 * 0.01 * 1.2682 = 6,341
- Denominator: 1.2682−1= 0.2682
- EMI: 6,341/0.2682= ₹23,652
Manual vs. Excel EMI Calculation
Here’s a comparison of Manual vs. Excel EMI Calculation:
Factor | Manual Calculation | Excel Calculation |
Formula | EMI=[P*R*(1+R)^N] / [(1+R)^N−1] | Excel Calculation = PMT (Rate, Nper, Pv) |
Error Probability | High possibility of human errors due to complex calculations | Less errors. Excel automates the formula, reducing the chances of errors. |
Convenience | Manual calculation is time-consuming. It requires multiple steps and careful calculations. | Quick and easy process. Excel offers automatic calculations with simple inputs. |
Execution Time | Takes long time to calculate complex datasets | Gives quick output regardless of the dataset size |
Best For
| Small-scale calculations or for educational purposes.
| Best for large-scale, professional, or quick financial analyses |
Amortization Table: Month-by-Month Breakdown
The EMI that you pay has two components- principal and interest. At the beginning of the loan repayment schedule, a majority portion goes towards interest payment. It keeps reducing gradually, as the principal component goes up.
Here is an example amortization table for Mr. X’s loan of ₹15,00,000 at a 12% annual interest rate for 5 years. We have considered the first 10 months in the table
Month | EMI | Principal Component | Interest Component | Outstanding Principal |
1 | 33,366.67 | 18,366.67 | 15,000.00 | 14,81,633.33 |
2 | 33,366.67 | 18,550.34 | 14,816.33 | 14,63,082.99 |
3 | 33,366.67 | 18,735.84 | 14,630.83 | 14,44,347.15 |
4 | 33,366.67 | 18,923.20 | 14,443.47 | 14,25,423.95 |
5 | 33,366.67 | 19,112.43 | 14,254.24 | 14,06,311.52 |
6 | 33,366.67 | 19,303.56 | 14,063.12 | 13,87,007.96 |
7 | 33,366.67 | 19,496.59 | 13,870.08 | 13,67,511.37 |
8 | 33,366.67 | 19,691.56 | 13,675.11 | 13,47,819.81 |
9 | 33,366.67 | 19,888.47 | 13,478.20 | 13,27,931.34 |
10 | 33,366.67 | 20,087.36 | 13,279.31 | 13,07,843.98 |
How Loan Tenure and Interest Rates Impact EMI
The loan tenure and interest rates impact the EMI that a borrower has to pay each month.
Impact of Loan Tenure on EMI
- Long Tenure: A longer loan tenure (5-10 years) reduces the monthly EMI because the loan amount is spread over more months. However, it results in higher total interest payments over the life of the loan.
- Shorter Tenure: A shorter tenure increases the EMI because the loan amount must be repaid in fewer months. But the total interest paid overtime will be lower, as the loan principal is cleared faster.
Example:
Loan Amount: ₹10,00,000
Interest Rate: 10% per annum
EMI for 5 years: ₹21,278
EMI for 10 years: ₹13,215
Although the EMI for the 10-year loan is lower, the total interest paid in the 10-year scenario will be higher.
Impact of Interest Rates on EMI
Changes in repo rate directly influence loan interest rates. If the RBI increases the repo rate, banks typically raise interest rates, leading to higher EMIs for floating-rate loans. Conversely, when the repo rate decreases, loan EMIs may reduce as banks pass on the benefit. Fixed-rate loans remain unaffected during their fixed term.
Higher interest rates can lessen the demand for loans, impacting the borrower’s spending and investment. On the other hand, lower interest rates encourage borrowing, boosting economic growth
For instance: You take a loan of ₹5 lakhs at an interest rate of 10% for a tenure of 3 years. The EMI for this loan would be approximately ₹16,134. If the interest rate increases by 2% to 12%, the EMI rises to ₹16,611. That’s an additional ₹477 every month. This shows how even a 2% rise in interest rates can significantly affect your monthly budget, especially for short-term loans.
To reduce the impact of changing interest rates, a borrower can opt for a longer loan tenure or make pre-payments to reduce the principal amount.
Also Read: Long Term Personal Loans
Conclusion
It is important to understand the components of a loan for effective EMI payments. While you can manually calculate interest rate and principal amount in EMI, you can use Zype’s EMI principal and interest calculator. Knowing how loan tenure and interest rate impact the EMI amount will help you select the right loan structure that best fits your financial needs.
Frequently Asked Questions
To Calculate Monthly Principal And Interest In EMI, use an EMI calculator or amortization schedule. In the early months, a larger part of EMI goes toward interest, and gradually more goes toward principal repayment.
You can use the formula: EMI = [P x R x (1+R)^N] / [(1+R)^N – 1]
Where P = Principal, R = Monthly interest rate, N = Number of months. To find how much of EMI is principal or interest, use an amortization chart or financial calculator.
If it’s simple interest: Interest = (Principal × Rate × Time) / 100. For compound or EMI-based loans, use an EMI calculator and input 8% annual interest (or 0.0067 monthly).
EMI = (P + SI) / N, Where SI = Simple Interest = (P × R × T) / 100,
and N = total number of months.
Let’s say ₹1,00,000 loan at 12% for 1 year. Monthly interest rate = 12 / 12 = 1% = 0.01
N = 12 months. EMI = [1,00,000 × 0.01 × (1+0.01)^12] / [(1+0.01)^12 – 1] ≈ ₹8,885
Monthly interest = (Loan amount × Annual rate) / 12. For ₹1,00,000 at 12%, monthly interest = (1,00,000 × 12%) / 12 = ₹1,000
Use an amortization schedule. In each EMI, interest = outstanding principal × monthly interest rate. Principal = EMI – interest.
- Flat rate: Interest is calculated on the full principal throughout.
- Reducing balance: Interest is calculated on the remaining balance. You pay less interest over time in reducing balance loans.
The principal amount is the original sum of money borrowed from the lender. It does not include interest or any fees. Your EMI helps repay both the principal and interest over time.