How to use
- Replace the example inputs with your loan and property figures.
- Select Calculate to update the estimate and any schedule.
- Change one assumption at a time, then compare the result with the earlier scenario.
How this calculation works
Each row starts with the prior balance. Monthly interest equals that balance times the annual rate divided by twelve. Principal is the payment minus interest. The closing balance becomes the opening balance for the next row. Calculations retain precision internally; the display rounds to cents.
Interest_t = Balance_(t−1) × annual rate ÷ 12
Worked example
Illustrative inputs — not a quote or a local average.
- Loan amount
- $320,000.00
- Interest rate
- 6.5 %
- Loan term
- 30 years
Monthly housing estimate: $2,022.62. Principal & interest: $2,022.62. Total interest: $408,142.36.
Reading the result
The balance chart shows the debt still owed, not the value of your home. Open the payment schedule to inspect the early and late allocation between interest and principal. The final payment can be smaller than the regular payment because it is capped at the remaining debt plus interest.
Before acting on the estimate
This schedule assumes monthly installments, an unchanged rate and no missed payments. It does not reproduce daily-interest servicing or a contractual rounding convention. A statement balance can therefore differ slightly even when the loan terms appear identical.

Questions, answered
Why is early principal repayment slow?
At the start, the larger balance creates a larger interest charge, leaving less of the same payment for principal.
Is the chart home equity?
No. Home equity also depends on property value and any other liens.