Loan Payment Calculator
Intro
This calculator estimates monthly loan payments, total interest, and payoff speed using a standard amortization formula. It also lets you test the effect of an extra monthly payment. It is useful for mortgages, auto loans, personal loans, and quick budgeting before you compare formal lender offers.
How it works
The standard monthly payment uses the amortization formula P x r / (1 - (1 + r)^-n), where
P is principal, r is monthly interest rate, and n is the number of
monthly payments. When an extra payment is added, the calculator simulates the loan month by month until the
balance reaches zero.
Limitations: this is an estimate only. It does not include origination fees, insurance, property tax, closing costs, variable-rate resets, or lender-specific rounding and disclosure rules.
Practical use scenarios
- Estimate monthly affordability before you apply.
- Compare shorter versus longer loan terms.
- See how extra monthly payments reduce interest and payoff time.
- Build a rough repayment plan before using lender documents.
Related tools
FAQ
No. Use it for planning only. Actual offers depend on fees, credit profile, taxes, insurance, and lender policy.
It adds the same extra amount every month and re-simulates the balance until payoff.
Yes. In that case the payment is simply the loan amount divided by the number of months.
No. Those costs vary and need separate treatment.