NumberTally Loan Calculator
Calculate the monthly payment, total interest, and true cost of any loan — with origination fees and extra payments factored in, plus your exact payoff date.
Advanced options
Upfront fee, added to the total cost.
Deducted from what you receive; raises the true APR.
What the monthly payment really covers
Every payment splits into interest — the lender's charge for the outstanding balance that month — and principal, which actually reduces what you owe. Because interest is calculated on the remaining balance, early payments are interest-heavy and later payments are principal-heavy, even though your payment amount never changes.
The "true cost" of a loan is the amount borrowed plus all interest plus any upfront fees. Origination fees are easy to overlook: a 1% fee on a $25,000 loan adds $250 to the cost before interest even starts. This calculator rolls everything into one honest number.
Why extra payments punch above their weight
Extra payments go straight to principal, which shrinks every future interest charge. On a 5-year loan, even $50 extra a month can cut several months off the term. The effect is strongest early in the loan, when the balance — and therefore the monthly interest — is highest. Try an amount in the advanced options to see your savings.
Frequently Asked Questions
How is the monthly payment calculated?
With the standard amortization formula: M = P·r(1+r)ⁿ / ((1+r)ⁿ − 1), where r is the monthly rate and n is the number of payments. The step-by-step box above shows it with your numbers.
What is an origination fee?
A one-time upfront charge from the lender, often 0.5–1% of the loan. It's part of the true cost even though it isn't in the monthly payment — which is why we add it to the total.
Does making extra payments save interest?
Yes — every extra dollar reduces principal immediately, so all future interest charges shrink. The comparison above shows exactly how much interest and time you'd save.
Is there a penalty for paying off early?
Some loans charge prepayment penalties, but most personal and auto loans don't. Check your loan agreement — if there's no penalty, extra payments are pure savings.
Fixed vs variable rate — which is this?
This calculator assumes a fixed rate for the whole term. Variable-rate loans can change, so treat the result as a snapshot at today's rate.