Mortgage payoff calculator with extra payments
Enter the current balance, rate and remaining term, then add optional monthly, annual or immediate principal. HitEquals compares payoff dates, total interest, savings and the accelerated schedule.
Inputs used by this calculator
Mortgage Payoff Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Current principal balance | 300,000 | 0.01 or greater | Supplies the current principal balance quantity used by the published equation or result breakdown. |
| Annual interest rate (%) | 6.5 | 0 to 100 | Supplies the annual interest rate (%) quantity used by the published equation or result breakdown. |
| Remaining term (years) | 25 | 0.0833333333 to 50 | Supplies the remaining term (years) quantity used by the published equation or result breakdown. |
| Extra principal each month | 200 | 0 or greater | Supplies the extra principal each month quantity used by the published equation or result breakdown. |
| Extra principal each year | 1,000 | 0 or greater | Supplies the extra principal each year quantity used by the published equation or result breakdown. |
| One-time principal payment now | 5,000 | 0 or greater | Supplies the one-time principal payment now quantity used by the published equation or result breakdown. |
Build the current baseline
Use today's principal balance and remaining term, not the original loan amount and original term. The baseline payment is recalculated as a fixed principal-and-interest payment.
How extra principal works
A lump sum lowers the starting balance; monthly extra accompanies every payment; annual extra is added every twelfth payment. Interest then accrues on the smaller balance.
monthly interest = balance × annual rate ÷ 12 ÷ 100Interest and time saved
The engine runs baseline and accelerated schedules separately. Savings are baseline interest minus accelerated interest; months saved compare their payoff lengths.
Apply payments correctly
Tell the servicer to apply extra money to principal and verify the next statement. The calculator cannot see suspense accounts or servicer processing rules.
Penalties and excluded costs
CFPB notes that some mortgages can charge a prepayment penalty under stated conditions. Review the note and disclosure. Escrow, taxes, insurance and opportunity cost are excluded.
What the Mortgage Payoff Calculator answers
Compare a current mortgage schedule with monthly, annual and one-time extra principal payments.
Use Mortgage Payoff Calculator when you know Current principal balance, Annual interest rate (%), Remaining term (years), Extra principal each month, Extra principal each year and One-time principal payment now and need the relationship expressed by the published equation.
Extra-payment options
| Option | Timing | Effect |
|---|---|---|
| Lump sum | Now | Lowers starting balance |
| Monthly extra | Every payment | Steady acceleration |
| Annual extra | Every 12th payment | Periodic reduction |
Frequently asked questions
Do extra payments reduce mortgage interest?
Yes when applied to principal, because later interest is calculated on a smaller balance.
Should I enter the original balance?
Use the current unpaid principal balance.
Can I combine extra-payment types?
Yes. The schedule applies all three entered options.
Does this include escrow?
No. It models principal and interest only.
Could a prepayment penalty apply?
Possibly. Check the note and servicer disclosure before paying extra.
What question does this Mortgage Payoff Calculator answer?
Compare a current mortgage schedule with monthly, annual and one-time extra principal payments.
What to keep in mind
Confirm servicer instructions and whether a prepayment penalty applies. Escrow, fees and changing rates are excluded.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.