Broker DaveExtra payment calculator
Every extra dollar you send to principal skips straight to the end of the loan. See exactly how many months a monthly or one-time extra payment saves you, how much interest disappears, and the full amortization schedule with and without it, side by side.
Your loan
30 yrs — 360 is a 30-year note, 180 a 15-year.
Where you are today
paid off in · estimated balance today $400,000 · 30 yrs left
Extra payments
Added to principal on top of your regular payment, every month for the life of the loan.
A single lump sum to principal — a bonus, tax refund, etc.
Down from 30 yrs — same rate, same required payment, $111,892 less interest.
What the extra payments do
- Balance today
- $400,000
- Time left before extra payments
- 30 yrs
- Monthly payment (P&I)
- $2,528
- Extra per month
- $200
- Total extra paid in
- $58,400
- Payoff — no extra payments
- 30 yrs
- Payoff — with extra payments
- 24 yrs 5 mos
- Time saved
- 5 yrs 7 mos
- Interest — no extra payments
- $510,178
- Interest — with extra payments
- $398,286
- Interest saved
- $111,892
Amortization schedule
See a full year-by-year breakdown of both schedules side by side.
Email me this analysis
Same goal, three different levers
Extra payments
No paperwork, no fee, no minimum. Send more than the required payment and the servicer applies the difference to principal — your payment stays the same, but the loan ends sooner and total interest drops.
Recast
A lump sum plus a servicer fee re-amortizes the balance over the time you have left, which lowers the required payment but keeps the same payoff date. The opposite trade-off — cash flow instead of speed.
Refinance
A brand new loan with a new rate, new term, new closing costs, a credit pull and an appraisal. Only worth it when rates have moved enough to pay for all of that.
Before you send extra principal
- Mark it principal-only — with your servicer, in writing if needed. Extra money sent without instructions can land in escrow or get applied to next month's payment instead of the balance.
- Check for a prepayment penalty. Rare on modern conventional loans, but worth a two-minute look at the note before sending a large lump sum.
- Extra payments don't lower your required monthly payment — that's what a recast is for. This calculator assumes you keep paying the original payment amount the whole way through.
- This calculator shows principal and interest only. Taxes, insurance and any mortgage insurance in your escrow payment don't change because you paid extra.
This calculator is educational and is not a loan offer, a rate quote, or a commitment to lend. Every figure is an estimate. David Lurvey, NMLS 410420.