Extra Payment Mortgage Calculator — $X More Per Month
Slide the extra-payment dial — months cut and interest saved at every level, plus a one-time lump sum on top.
Formula
Disclaimer: Indicative math — lenders differ on day-count, rounding, fees and how extra payments are applied. Confirm with your servicer; this is not financial advice.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Need extra payment mortgage calculator results fast? Skip the spreadsheet and get a clear, defensible answer in one step — free, private and instant, recalculating live as you change any input.
About Extra Payment Mortgage Calculator — $X More Per Month
The extra-payment table is this tool's reason to exist: on $250,000 at 6% with 30 years to run, $50 a month saves ~$29,000; $200 saves ~$86,000 and nearly eight years; $500 saves ~$146,000 and over thirteen years. The relationship is strongly nonlinear in time but the per-dollar efficiency falls as the extra grows — the first $100 of extra payment is the most valuable $100, which is encouraging news for anyone who can't spare $500. Early-term extras massively outperform late-term ones. In year two of a 30-year loan, almost every payment dollar is interest, so a principal dollar removed avoids nearly three decades of compounding; by year 25 the same dollar avoids only a few years. If you'll ever prepay, the cheapest interest you'll ever kill is available right now — and conversely, aggressive prepayment in the final years is mostly symbolic. The lump-sum input models windfalls — bonus, RSU vest, inheritance — applied today. Combine and compare: a $10,000 lump now versus $200/month often lands surprisingly close over a full term, but the lump wins if applied early and the monthly wins for discipline. Whatever you choose, verify the servicer applied it to PRINCIPAL (statements should show the balance drop immediately), and keep your emergency fund intact — home equity is the least liquid place your money can live.
How to use Extra Payment Mortgage Calculator — $X More Per Month
- 1Enter Loan balance, Interest rate (%), Years remaining (years), Extra per month, One-time lump sum now into the Extra Payment Mortgage Calculator.
- 2The result is computed automatically using Extra principal removes balance from EVERY future month's interest computation — small monthly extras early in the term outperform large ones late — there is no button to press; it updates live as you type.
- 3Change any input to model a different scenario, then use “Copy result link” to share the exact numbers.
Why use Extra Payment Mortgage Calculator — $X More Per Month?
- ✓Computes extra payment mortgage calculator instantly with the correct formula — no spreadsheet needed
- ✓100% free and unlimited, with no sign-up, login or paywall
- ✓Runs entirely in your browser, so the figures you enter are never uploaded or stored
- ✓Shows the formula, a live worked example and references so you can defend the number
Frequently asked questions
Is $200/month extra really worth it?+
At the defaults it deletes ~$86,000 of interest and ~7.8 years of payments — a 30% cut in total interest for a 13% bump in monthly outlay. The honest comparison is against alternatives: at a 6% note rate the prepayment 'earns' a guaranteed 6% after tax, which beats savings accounts and rivals balanced portfolios with zero risk. Below ~4% note rates the answer flips for most people — invest the $200 instead.
Lump sum now or spread monthly — which saves more?+
Applied at the same time-point, the lump always wins (the whole amount stops accruing interest immediately rather than trickling in). The schedule table quantifies the monthly route; toggle the lump input to compare. Practical hybrid: throw windfalls at principal as they arrive AND automate a modest monthly extra — the lump does the heavy lifting, the monthly maintains momentum and habit.
Should extra money go to the mortgage or higher-rate debt first?+
Rate order, always: credit cards (20%+), personal loans (10–15%), then auto, THEN a 6% mortgage. A dollar prepaying a 24% card saves four times the interest of the same dollar on this mortgage. Also fund the 401(k) match (an instant 50–100% return) and a basic emergency fund before locking money into home equity — extra mortgage principal can't be un-paid when the transmission fails.
Do extra payments lower my monthly payment?+
No — they shorten the TERM; the required payment stays fixed (that's amortization). If you want a lower required payment after a big principal cut, ask for a RECAST: for a small fee (~$250) the servicer re-amortizes the new balance over the remaining term. Recast + keep paying the old amount = lower obligation, same acceleration — the best of both, and far cheaper than refinancing when your existing rate is good.
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