PayoffTable

Loan Amortization Calculator

Not every amortizing loan is a mortgage. Cars, RVs, boats, and personal loans all run on the identical math — this calculator handles all of them with the full monthly schedule.

Reviewed by the PayoffTable editorial team · Updated 2026-10-24

Your numbers

Amount you borrow
Annual rate on the loan
In years

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Every fixed-rate installment loan amortizes the same way: a fixed payment, monthly interest on the declining balance, and whatever remains going to principal. A 72-month auto loan and a 30-year mortgage are the same machine at different scales — which is why dealers' finance offices and mortgage servicers produce tables that look identical.

That also means the levers are identical. A shorter term, a lower rate, or extra principal payments produce the same dramatic interest savings on a car loan as on a house. On a $45,000 auto loan at 8.9% for 72 months, an extra $75 a month cuts seven months off the loan and $1,524 of interest — and simply choosing a 60-month term instead saves $2,325.

If your loan is specifically a mortgage, the mortgage version frames the numbers with mortgage-specific guidance. Otherwise, everything you need is here: schedule, chart, print, CSV.

How loan amortization works

The payment formula is universal across installment loans:

M = P · r(1+r)ⁿ / ((1+r)ⁿ − 1) r = APR ÷ 12, n = months

Short terms change the shape dramatically. Because the balance falls faster, interest has less time to accumulate — which is why a 36-month auto loan costs a fraction of the interest of a 72-month loan at the same rate, even though the monthly payment is roughly double.

One warning specific to installment loans: simple-interest auto loans accrue interest daily, so paying late costs more and paying early saves more than a monthly model shows. The schedule here is the contractual month-by-month view; your per-diem accrual will differ slightly between payment dates.

Worked example. Auto loan $45,000 at 8.9% for 72 months: payment $808.92, total interest $13,242.07. Same loan over 60 months: payment $931.94, total interest $10,916.61 — $2,325.46 saved for $123.03 more per month. Add $75/month extra on the 72-month loan: payoff in 65 months (May 2031), interest $11,717.81 — $1,524.26 saved.

Terms & definitions

Amortization
The process of paying off a loan with scheduled payments that cover both interest and principal. Early payments are mostly interest; later payments are mostly principal.
Principal
The amount you borrowed and still owe. Extra payments reduce principal directly, which shrinks every future interest charge.
APR
Annual Percentage Rate — the yearly cost of the loan including fees. Your monthly interest charge uses the note rate, which is usually a touch lower.
Term
The number of years the loan is scheduled to last. A 30-year term has lower payments but roughly double the total interest of a 15-year term at the same rate.

Frequently asked questions

Does this work for auto loans?
Yes — enter the amount financed, APR from your contract, and term in months ÷ 12. Most auto loans are simple-interest installment loans that amortize exactly like the schedule shown here.
What about interest-only or balloon loans?
No — this calculator handles fully amortizing loans only. Interest-only loans have a flat principal balance until the balloon or reset, which is a different structure. If you have a balloon, model the amortizing phase here with the balloon treated as a lump sum.
Why does my lender's payoff quote differ from the final balance here?
Payoff quotes include per-diem interest from the last payment to the payoff date, plus any fees. The schedule's final balance is the principal owed after the last scheduled payment; a mid-cycle payoff adds a few days of interest.
Can I use this for a mortgage?
Yes, mathematically — but the mortgage amortization calculator includes mortgage-specific guidance on escrow, servicers, and prepayment rules that does not apply to other loans.

References

  1. CFPB — What is a simple-interest loan?
  2. CFPB — What is an amortization schedule?
  3. Federal Trade Commission — Financing a car
Educational content only — not financial, tax, or legal advice. Your loan terms govern; confirm details with your servicer.

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