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Plain Numbers

Mortgage

Mortgage payoff planner

Enter your loan, add extra principal payments in the schedule, and line up refinance options side by side. Figures cover principal and interest only; taxes and insurance are left out.

These are example numbers. Replace them with your own balance, rate and remaining term.

Scenario name

Type

Remaining term

Copy the numbers from your latest statement and the remaining term is worked out for you.

Remaining balance

$

Interest rate

%

P&I payment

$

Remaining term

yrs

mo

Next payment due

Extra principal every month

$

Applies to every row unless you type a different amount in the schedule.

Monthly P&I

Paid off

Interest left to pay

Saved by extra payments

Add extra payments to the schedule

Fills the Extra column below. You can also type straight into any row, or paste a column of numbers from a spreadsheet.

Amount

$

How often

Starting

For how many

Compare scenarios

Balance remaining over time, including each scenario's extra payments.

Compare against

Scenario	Rate	Monthly P&I	Extra paid	Paid off	Interest	Closing costs	Interest + costs	Difference	Break-even

Difference and break-even compare total interest plus closing costs with the reference scenario. Break-even is the month when the cumulative savings first cover the closing costs.

Prepay or invest?

Every extra dollar of principal earns your mortgage rate, risk-free. Here’s how that compares with a Treasury of about the same length, after your taxes.

Prepaying earns

Treasury after tax

I itemize and deduct my mortgage interest

Treasury interest owes federal tax and NIIT but no state tax. Uses the Treasury maturity closest to the loan’s remaining term, up to 10 years, since most mortgages are paid off or refinanced well before they mature.

Amortization schedule

Edit the Extra column to add or change a payment for any month. Highlighted cells are your edits. Enter and the arrow keys move between rows.

#	Month	Payment	Extra	Interest	Principal	Balance

How the planner works

Each month, interest is the balance times the annual rate ÷ 12, rounded to the cent. The rest of the payment, plus any extra you enter, comes off principal. Extra payments stop once the loan is paid off.

From my statement

Most statements don’t show the remaining term. Enter the principal balance, rate and monthly principal-and-interest payment, and the planner works out how many payments are left. The final payment date should match your statement’s maturity date to within a month.

Comparing a refinance

“Interest + costs” adds closing costs to the interest you’d pay. Break-even is the first month when the refinance’s cumulative interest plus closing costs drops below the reference loan’s cumulative interest. Rolling costs into the loan means you pay interest on them too.

Saving and sharing

Your scenarios are saved in this browser automatically. “Copy share link” puts the whole plan into the link itself, so the person you send it to sees exactly your numbers without anything being stored on a server. YAML export gives you a file you can keep or edit by hand.