What is Loan Calculator?
A loan calculator computes the required equal monthly installment (EMI) necessary to fully amortize an installment debt over a predetermined schedule at a fixed interest rate.
How to Use This Calculator
- Enter the principal amount you intend to borrow.
- Specify the loan term in months or years.
- Enter the lender’s nominal interest rate (APR).
- View your monthly obligation and total interest payable.
The Mathematical Formula & Variables
Variables Definition
| Symbol / Variable | Name | Description |
|---|---|---|
PMT |
Periodic Payment | Monthly loan installment. |
P |
Principal | Initial loan amount. |
r |
Periodic Rate | Annual interest rate / 12. |
n |
Periods | Total number of monthly payments. |
Step-by-Step Worked Example
Scenario: Borrowing $25,000 for 5 years (60 months) at 7.0% annual interest.
- Monthly rate r = 0.07 / 12 = 0.005833.
- Number of payments n = 60.
- Discount factor 1 - (1 + 0.005833)^(-60) = 0.31604.
- Monthly payment = ($25,000 * 0.005833) / 0.31604 = $461.45.
- Total paid = $461.45 * 60 = $27,687. Total interest = $2,687.
Result: Monthly payment is $461.45. Total financing cost is $2,687.00.
Frequently Asked Questions
Can I pay off my loan early without penalty?
Most modern consumer and personal loans do not have prepayment penalties, but you should always review your lender agreement before making early lump-sum payoffs.
How does the loan term impact total interest paid?
Shorter loan terms require higher monthly installments but accrue significantly less interest. Longer terms lower the monthly burden but cost much more over the life of the loan.
What is the difference between simple interest and precomputed interest?
Simple interest calculates daily or monthly on remaining balance, meaning early payments reduce total interest. Precomputed interest fixes total charges upfront regardless of early payoff.