Loan Payoff Calculator
See what extra payments actually save you, and compare up to 3 scenarios by true total cost — not by monthly payment or interest rate alone.
Scenario B
Scenario C
Loan balance over time
Amortization schedule
Approximation only. Not financial advice.
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How it works
1
Enter your loan
Amount, rate, term, and any fees. Standard French amortization.
2
Add extra payments
Recurring, one-time, or biweekly-equivalent — combined in the same simulation.
3
Compare up to 3
See the true total cost side by side. The lowest wins, not the lowest rate.
What this calculator actually does
Most loan calculators stop at the monthly payment. That number matters, but it hides the two things you actually pay: total interest and any fees baked into the loan. This calculator shows all three, and lets you see how extra payments — a recurring $50, a $2,000 tax refund thrown at month 12, or switching to a biweekly-equivalent schedule — change the outcome.
Every scenario is computed with standard French amortization: your payment stays constant, but the split between interest and principal shifts month by month. Each extra dollar goes straight to principal and permanently lowers the balance the next interest charge is computed against. That's why a small recurring extra shaves years off long-term loans.
How to compare loans honestly
Comparing by interest rate alone is misleading: a loan with a lower APR but a $600 origination fee and $18/month mandatory insurance can cost more over its life than a higher-rate loan with no fees. Comparing by monthly payment alone is worse — a longer term always lowers the payment while raising the total cost. This tool measures the only thing that matters: true total cost = principal + all interest + all fees actually paid.
The 3-scenario view is designed for the real decisions you face: "Should I take the shorter term at a higher rate?", "Is it worth refinancing?", "Does that promotional rate survive the origination fee?", "What if I put $100 extra per month?". Set them up side by side, and let the numbers pick.
Extra payments — when they help most
Extra payments help most when made early. On a 30-year mortgage, an extra $100/month in year 1 saves far more interest than the same $100/month starting in year 20 — because you're cutting into the years where the interest slice of each payment is largest. This calculator will show you exactly how much and how many months, in real time.
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Frequently asked questions
Is this a mortgage calculator or a personal loan calculator?
Both. Any fixed-rate installment loan with periodic payments works: mortgages, personal loans, auto loans, student loans. The math is the same.
How much can I really save with extra payments?
It depends on your rate and term, but the effect is often bigger than people expect. On a 30-year, 6% mortgage, a $100/month extra can save 4–6 years and tens of thousands in interest.
Should I choose the lowest monthly payment or the lowest rate?
Neither, on its own. Lowest payment usually means the longest term, which raises the total cost. Lowest rate can be undercut by origination fees. Use this calculator's true total cost.
What is biweekly-equivalent?
Splitting the monthly payment into two half-payments every 2 weeks means 26 half-payments a year — one full extra monthly payment slipped in without noticing.
Is my data sent anywhere?
No. The calculator runs entirely in your browser. Amounts, rates, dates — nothing is uploaded.
Is this financial advice?
No. This is a math tool. Whether a decision is right for you depends on your job stability, other debts, emergency fund and tax situation — talk to a licensed advisor.
Why does the winner sometimes have a higher monthly payment?
Because a higher payment on a shorter term usually pays far less interest overall. The tool measures the total you actually pay across the whole loan, not the monthly cost.
Can I save or share my scenarios?
The current version keeps scenarios in the page while you use it. Printing the amortization schedule is supported. A share link (URL with the numbers) is planned for a future update.