Loan Interest Calculator
Calculate the total interest and monthly payments for a loan based on principal, annual interest rate, and loan term.
Published by:
isCalculator Editorial Team
Was this calculator helpful?
How to use this tool?
Follow these steps to calculate your loan interest:
- Enter Loan Amount ($) – Input the total amount you plan to borrow (e.g., 10000). Must be a positive number.
- Enter Annual Interest Rate (%) – Provide the yearly interest rate as a percentage (e.g., 5 for 5%). Must be positive.
- Enter Loan Term (Years) – Specify the repayment period in years (e.g., 5). Must be positive.
- Click "Calculate" – Press the blue button to compute results.
Results displayed:
- Monthly Payment – Fixed amount due each month.
- Total Interest – Total interest paid over the loan term.
- Total Payment – Sum of principal and interest.
Note: All inputs must be positive numbers. The calculator uses the standard amortization formula with monthly compounding.
Previous Results
| Result | Inputs | Date |
|---|
Frequently Asked Questions
The monthly payment is calculated using the formula: M = P * (r * (1 + r)^n) / ((1 + r)^n - 1), where P is the loan amount, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments (years times 12).
If the interest rate is zero, the monthly payment is simply the loan amount divided by the number of months. The total interest will be zero.
Yes, this calculator works for any fixed-rate loan, such as mortgages, car loans, or personal loans, as long as the interest rate remains constant throughout the term.
