Mortgage Payoff & Extra Payment Dashboard

How to use the Mortgage Payoff & Extra Payment Dashboard

1. Enter your current balance, interest rate and remaining term from your latest statement (and the next payment date).
2. Leave the monthly payment at 0 to calculate principal and interest, or enter your actual P&I payment.
3. Add extra monthly principal, an annual extra, a lump sum, the biweekly option or dated custom payments.
4. Optionally add taxes, insurance, HOA and mortgage insurance to see your full housing payment; they do not change payoff.
5. Compare payoff dates and interest saved, then use 'Pay off or invest?' to compare prepaying with investing the same cash.

What's included

• Standard amortization for existing balances and remaining terms, including 0% loans
• Extra monthly principal, annual extras, lump sums, biweekly plans and dated custom payments
• Interest saved, accelerated payoff date, time saved and total extra paid
• Taxes, insurance, HOA and PMI shown separately — never treated as principal
• Comparison of no extra, $100, $250, $500 and your own monthly extra
• Pay off the mortgage or invest? comparison with tax and fee assumptions
• Excel amortization workbook and extra-payment calculator with live formulas and charts, plus PDF and CSV

How the amortization works

For a fixed-rate loan, each payment first covers the month's interest — the balance times the annual rate divided by 12 — and the rest reduces principal. Extra principal is applied after the scheduled payment and is capped at what is owed, so the final payment can be smaller than usual. A 0% rate is handled as equal principal payments. Only fixed-rate mortgages are modeled; for an adjustable-rate loan the results would change at each rate reset.

Escrow and housing costs

Property taxes, homeowners insurance, HOA dues and mortgage insurance are part of what many borrowers pay each month, but they are not principal and do not shorten the loan. The dashboard shows them separately so the total monthly housing cost is clear without overstating payoff progress.

Biweekly payments

Paying half the monthly payment every two weeks produces 26 half-payments, or 13 full payments, a year. The dashboard models this as one extra monthly payment spread evenly over the year. Some lenders hold half-payments until a full payment is received or charge program fees, so confirm how yours applies them.

Pay off the mortgage or invest?

Option A puts the extra cash toward principal and, once the loan is gone, invests the freed-up payment. Option B keeps the scheduled payment and invests the extra cash every month. Interest saved on a fixed-rate mortgage is relatively predictable; investment returns are uncertain and can be negative. The break-even return shows what an investment would need to earn, after your tax and fee assumptions, to match prepaying. Liquidity, emergency savings, other debts, employer matches and taxes also matter — neither choice is always better.

User inputs, assumptions and results

Inputs come from your loan statement and plans. Assumptions include fixed rates, payment timing and the biweekly approximation. Results are calculated from standard amortization mathematics; no current mortgage rates are built in. Check your lender's rules on prepayment and any prepayment penalty.

Key formulas

Monthly payment (P&I) = B × r ÷ (1 − (1 + r)^−n), r = annual rate ÷ 12; if r = 0, payment = B ÷ n
Each month: interest = balance × r
            scheduled principal = min(balance, payment − interest)
            extra principal = min(remaining balance, extras due this month)
Biweekly plan ≈ 13 payments a year = payment ÷ 12 extra each month
Interest saved = total interest (standard) − total interest (with extras)
Break-even investment return = mortgage rate ÷ (1 − tax on gains) + investment fees

Worked example (the dashboard's illustrative defaults)

1. Independent check: a $200,000 loan at 6% for 30 years has a principal and interest payment of $1,199.10 and about $231,676 of total interest — the dashboard returns the same figures.
2. Default plan: a $375,400 balance at 6.5% with 302 payments left (next payment December 2026) has a P&I payment of about $2,528.03 and about $388,065 of remaining interest, paid off in January 2052.
3. Adding $200 a month of extra principal ($50,600 in total) pays the loan off in January 2048 — 48 payments sooner — and saves about $72,635 of interest.
4. For comparison, $100 extra saves about $40,506 and $500 extra saves about $139,415. With $650 a month of taxes and insurance, the total housing payment is about $3,178 before extras.

Escrow does not reduce principal. Confirm your lender applies extra payments to principal and whether any prepayment penalty applies.

Sources

• Consumer Financial Protection Bureau — Owning a home
• Consumer Financial Protection Bureau — Consumer tools
• Investor.gov (SEC) — Understanding fees

Frequently Asked Questions

How much interest does an extra mortgage payment save?

It depends on your balance, rate and how early the extra is paid. In the default example, $200 a month on a $375,400 balance at 6.5% saves about $72,635 and four years. Enter your own loan to see your figure.

Is a biweekly mortgage plan worth it?

Paying half the payment every two weeks adds roughly one extra monthly payment a year. You can get the same effect by adding one-twelfth of your payment each month. Check for program fees and how your lender applies half-payments.

Do property taxes and insurance reduce my mortgage balance?

No. Escrow payments for taxes and insurance, HOA dues and mortgage insurance are housing costs. Only principal payments reduce the loan balance.

Should I pay off my mortgage early or invest?

Prepaying a fixed-rate loan saves interest at the loan rate with little uncertainty but ties money up in home equity. Investing may earn more or less, with risk. The dashboard compares both under your assumptions; consider liquidity, emergency savings, other debt and taxes. Neither is always better.

Does it work for adjustable-rate mortgages?

No. The dashboard models fixed-rate mortgages only. An adjustable-rate loan's payment and interest change at each reset.

Can I use it without an account?

Yes. All calculations and downloads work without signing in. A free account is optional for saving plans privately; nothing you enter is placed in the page address.