How to estimate a fixed monthly loan payment
Understand principal, interest, term and the costs that a basic repayment estimate does not include.
When considering a fixed-rate loan, the monthly payment is often the easiest figure to compare. An amortization formula estimates that payment from the principal, annual interest rate and loan term.
The three required inputs
Principal is the amount you receive and must repay. The annual interest rate is the stated yearly rate. The term describes how many years or months the loan will continue.
The calculator converts the annual rate into a monthly rate, then distributes principal and interest into equal payments. When the rate is zero, principal is simply divided by the total number of months.
A simple example
For a loan of 120,000 over five years at a fixed annual rate of 8%, enter:
- Loan amount: 120,000.
- Annual rate: 8.
- Term: 5 years.
The result estimates the monthly payment and total interest over the term. Change the term to see how a lower monthly payment may lead to higher total interest.
Costs not included
A basic estimate usually excludes application fees, insurance, early repayment charges, taxes and rates that change after an introductory period. Lenders may also use different collection dates or calculation rules.
Treat the result as a starting point for budgeting and comparing scenarios. Before signing an agreement, request a complete repayment schedule and the real total cost from the lender.
Use the estimate carefully
Try at least three scenarios: a short term, the expected term and a longer term. Leave room in the budget for lower income or higher living costs. The smallest monthly payment is not always the least expensive option when it creates much more interest over time.