A little extra now More freedom later.
Model extra payments and payoff savings.
Interest you could keep
Compared with this exact loan without extra payments.
Your path to mortgage-free.
With extrasDashed line: original schedule. Solid line: your plan. Tax and insurance costs continue after payoff. The interest savings above exclude possible PMI savings and opportunity cost. Confirm how your servicer applies principal payments.
Extra principal shortens the payoff schedule; it does not lower your required payment. Keep enough cash for emergencies before committing.
Try biweekly payments
Half your principal-and-interest payment every 2 weeks totals 26 half-payments a year, one extra monthly payment spread across the year.
Some servicers charge fees for biweekly plans or hold payments until a full monthly amount accrues. Confirm how your servicer applies extra principal.
Simulate a recast
A recast applies a lump sum to your balance, then re-spreads the remaining balance over the remaining months at the same rate, lowering the payment without a new loan.
Not all servicers offer recasting, and some charge a fee. Confirm eligibility before counting on this.
Build the payment before you compare it
Follow the assumptions into the result so a single headline number never stands alone.
- 01Price the paymentEnter price, down payment, rate, term, and closing assumptions.
- 02Open the breakdownSeparate principal, interest, taxes, insurance, HOA, PMI, and cash due.
- 03Compare scenariosUse schedule, payoff, or comparison views with the same assumptions.
How the calculation works
Each modeled month adds $200 of extra principal to the standard payment computed for the default $340,000, 6.25%, 30-year loan.
Extra principal reduces the balance the very month it is applied, so every later month accrues interest on a smaller balance and reaches payoff sooner than the scheduled 360 months.
Worked example
Worked example: $200 extra principal every month. Same $340,000, 6.25%, 30-year loan as the default purchase, with an extra $200 applied to principal each month starting with the first payment.
- Without extras, the loan runs the full 360 months and accrues about $413,637.85 in total interest.
- With $200 extra every month, the loan pays off in about 285 months instead of 360.
- Total interest with the extra payments drops to about $312,950.65.
Modeled result: about 75 fewer months (roughly 6.25 years) and about $100,687.20 less interest.
Assumptions
- Extra principal is applied immediately after the regular payment, with no recast, no prepayment penalty and no change to the required scheduled payment.
- The note rate and original term stay fixed for the life of the loan.
When to use this
Use this page to see how a specific extra-payment plan changes your payoff date and lifetime interest before committing to it with your servicer.
Common mistakes
- Assuming an extra payment lowers the required monthly payment; in this model it shortens the loan instead.
- Treating the modeled monthly-extra approximation as a true biweekly payment schedule.
Big decisions. Clearer answers.
What is actually in a mortgage payment?
Separate principal and interest from taxes, insurance, HOA, PMI and upfront closing cash.
15-year or 30-year mortgage: compare the right numbers.
Compare required payments, interest costs and the flexibility of extra payments on 15-year and 30-year fixed mortgages.
PMI removal: a request is not the automatic date.
Understand the difference between requesting conventional PMI cancellation at 80% and automatic termination on the original schedule.
Give every extra dollar a job.
This tool compares your loan with and without extra principal using the same rate and original term. Monthly extras start with the first modeled payment. Annual extras arrive at every twelfth payment, and a lump sum arrives in the payment month you choose. The final payment is capped at what you actually owe. If you are modeling an existing loan, use its remaining principal as the loan amount and its remaining term; the primary form is otherwise designed for a new purchase.
A few things you
might be wondering.
No fine-print scavenger hunt required.
Read the full methodology
Will an extra payment lower my required monthly payment?
Not in this model. The scheduled principal-and-interest payment stays the same while the loan ends sooner. A lender-approved recast is a different process and is not modeled.
How are annual extras timed?
After the regular payment in months 12, 24, 36 and so on. A one-time extra is applied after the regular payment in its selected month.
Are these true biweekly payments?
No. Dividing one regular payment by 12 and paying that amount extra each month is a monthly approximation to one additional annual payment, not a true biweekly schedule.
What should I check with my servicer?
Ask how to designate money as principal-only and whether your loan has a prepayment penalty. The model assumes extra principal is applied immediately after each scheduled payment without fees.
Source references: CFPB: Loan Estimate explainer
Sources checked 2026-09-11. Educational software; no professional review claimed.
A home for your plans.
Explore the numbers before you make the next move.