About the Payment Calculator
A payment calculator finds the monthly payment for any loan amount, rate, and term. It is the first calculation to run when considering borrowing, because the monthly payment is what your budget actually has to absorb.
The formula
M = P · [ r(1 + r)ⁿ ] / [ (1 + r)ⁿ − 1 ]P is the principal, r the monthly rate (annual divided by 12), and n the total number of payments. The payment stays constant while its split between interest and principal shifts.
How to use this calculator
- 1Enter your Loan Amount ($). The field starts at
20000, which you can overwrite. - 2Enter your Annual Interest Rate (%). The field starts at
7, which you can overwrite. - 3Enter your Loan Term (Years). The field starts at
5, which you can overwrite. - 4Read the result straight away — it recalculates as you type, so there is no button to press. Use Share to copy a link that reopens the page with your exact numbers filled in.
Worked example
| Input | Value |
|---|---|
| Loan Amount ($) | 20000 |
| Annual Interest Rate (%) | 7 |
| Loan Term (Years) | 5 |
Result
Monthly Payment: $396.02
Total Paid: $23761.44
Total Interest: $3761.44
Interest as % of Loan: 18.81%
Those are the values the page loads with, so you can reproduce this result yourself and then change one field at a time to see what drives the outcome.
Understanding your result
The payment is fixed but its composition changes throughout the loan. Early payments are mostly interest because interest is charged on a large outstanding balance; later payments are mostly principal. This is why paying off a loan halfway through does not mean you have repaid half the balance.
Rate and term interact in ways that make comparison shopping worthwhile. Dropping the rate by a point lowers the payment modestly; extending the term lowers it more but costs more overall. Running several combinations here shows which trade-off actually suits your situation.
Things worth knowing
- Budget against the full obligation — insurance, tax, and fees are often billed separately from the loan payment.
- Confirm whether the quoted payment includes any required insurance products.
- Keep total debt payments under roughly 36 percent of gross income to stay within lending norms.
- Ask for the total of payments as well as the monthly figure. Lenders must disclose it.
- A larger deposit reduces both the payment and the total interest, since you borrow less.
Frequently asked questions
How do I calculate a monthly payment?+
Apply the amortising payment formula using the principal, the monthly interest rate, and the number of payments. The result covers principal and interest but excludes taxes, insurance, and fees.
Why is my actual payment higher than calculated?+
Because lenders often bundle escrow items — property tax, insurance, mortgage insurance — or add fees. Ask specifically for the principal-and-interest portion when comparing.
How much can I afford to borrow?+
Lenders generally want total monthly debt payments below 36 to 43 percent of gross income. Work backwards from a payment you can comfortably afford rather than from the maximum offered.
Does the payment change over time?+
Not on a fixed-rate loan. Variable-rate loans reprice when the index moves, and escrow-inclusive payments change as tax and insurance costs are reassessed.