Loan Calculator
Comparing payoff plans for auto, personal, and other loans
Any fixed-rate installment loan — auto, personal, student, or otherwise — follows the same amortization mechanics as a mortgage, just usually over a shorter term and smaller principal. Enter the amount, interest rate, and term, and the loan's monthly payment, total interest, and payoff date are all fully determined by that math; there's no guesswork involved, just arithmetic most people don't do by hand.
The part that changes outcomes the most, and that a lot of loan calculators skip, is modeling extra payments. Because interest each period is charged on the outstanding balance, an extra payment applied to principal shortens the remaining schedule and removes interest that would otherwise have accrued on that balance for the rest of the term — the earlier the extra payment, the bigger the effect.
LoanClarity was built around that specific what-if: a live slider that adds a hypothetical extra monthly payment and shows, instantly, how much interest that removes and how much sooner the loan is paid off — alongside the full month-by-month amortization schedule, entirely offline.
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Frequently asked questions
How is a loan's monthly payment actually calculated?
Fixed-rate installment loans use a standard amortization formula based on the principal, the periodic interest rate, and the number of payments — the same payment amount each month covers a shrinking interest portion and a growing principal portion as the balance declines. This is deterministic math, not an estimate, once the rate, amount, and term are fixed.
Is it always worth making extra payments on a loan?
Structurally, extra principal payments always reduce total interest on a standard amortizing loan, since they shrink the balance interest is calculated on going forward. Whether it's the best use of that money depends on factors outside the loan itself — like whether the loan has a prepayment penalty, and whether that money could earn more elsewhere — which is a personal financial decision, not something a calculator can answer for you.
What does an amortization schedule actually show?
A month-by-month (or payment-by-payment) breakdown of exactly how much of each payment goes to interest versus principal, and what the remaining balance is after that payment — letting you see precisely when the interest/principal split crosses over and how the balance declines to zero by the end of the term.