Generate complete mortgage amortization schedules — annual or monthly. See principal vs interest breakdown, crossover point, and cumulative interest over time.
An amortization schedule is the complete payment-by-payment breakdown of a mortgage, showing exactly how much of each payment goes to principal and how much goes to interest. Early in the loan, interest dominates — on a typical 30-year mortgage at 6.75%, about 75% of each early payment goes to interest. This gradually shifts until a crossover point where principal exceeds interest.
Understanding amortization is crucial for financial planning. It explains why refinancing makes sense (resetting the clock increases interest), why extra payments in early years are so powerful (the balance is highest), and why the loan feels like it barely moves in the first decade.
This calculator generates a full amortization schedule in annual or monthly view. The visual principal-vs-interest bars show the ratio shifting over time, and key milestones like the crossover point and 50% payoff date provide clear goalpost markers. Whether you are evaluating a new mortgage, considering extra payments, or comparing loan terms, the amortization schedule tells the full story.
Most mortgage quotes only show the monthly payment. The amortization schedule reveals the hidden reality — how much interest you actually pay, when principal begins to dominate each payment, and how long until you reach meaningful equity. This transparency drives better financial decisions. Keep these notes focused on your operational context.
Payment = P × r(1+r)^n / [(1+r)^n − 1]. For month m: Interest = Balance × r/12, Principal = Payment − Interest, New Balance = Balance − Principal.
Result: Payment: $2,271/mo — Total interest: $467,412 — Crossover: Year 18.5 — 50% payoff: Year 21.8
A $350K mortgage at 6.75% for 30 years costs $2,271/month (P&I). You pay $467K in interest — 134% of the loan amount. Principal exceeds interest in each payment starting around year 18.5. The 50% payoff milestone is not reached until year 21.8 — well past the two-thirds mark of the loan.
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Amortization is the process of paying off a loan through equal periodic payments over a fixed term. Each payment is split between interest (charged on the outstanding balance) and principal (reducing the balance). Over time, the interest portion shrinks and the principal portion grows as the balance decreases.
Interest is calculated on the outstanding balance. Early in the loan, the balance is highest, so interest charges are maximized. As you pay down principal, the balance drops and less interest accrues, allowing more of each equal payment to go toward principal reduction.
The crossover point is the month when the principal portion of your payment first exceeds the interest portion. For a 30-year mortgage at 6-7%, this typically occurs around years 17-20. Before crossover, you are paying more interest than principal; after crossover, the reverse is true.
For a fixed-rate mortgage, the total P&I payment stays constant every month. What changes is the split between principal and interest within that payment. However, if you have an adjustable-rate mortgage (ARM), the total payment may change when the rate resets.
Refinancing restarts the amortization clock with a new loan. Even if you lower your rate, the new loan starts with high interest allocation again. If you have been paying for 10 years, you have already paid the most expensive interest. Refinancing to a lower rate only saves money if the rate reduction outweighs the cost of restarting amortization.
Extra principal payments reduce the balance faster, shifting the amortization schedule in your favor. Even small extra payments ($100-200/month) can shave years off the loan and save tens of thousands in interest. The effect is strongest when made early, before the crossover point.