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See exactly how many years and how much interest you'll save by adding to your mortgage — with monthly, annual, one-time, and biweekly extras, plus an opportunity-cost check against investing.
Refreshed daily from Freddie Mac PMMS (weekly survey) · data as of October 15, 2026
Updated monthly from Bank of England (IADB) · latest data September 30, 2026
Updated monthly from ECB Data Portal · latest data August 2026
Updated monthly from Reserve Bank of Australia (F5/F1.1) · latest data September 30, 2026
Reference figure (hand-reviewed June 2026) — not auto-fetched
Rates shown are national averages for reference only. Actual rates vary by lender, credit score, and LTV. US 30/15-yr figures come from the Freddie Mac PMMS public dataset. UK (Bank of England), Euro area (ECB) and Australia (RBA) figures come from official statistics that publish monthly, so they lag by several weeks; each card shows its own latest period. If a source can't be reached, the card keeps the last figures it fetched successfully. Canada is a reference figure only. Countries without one credible national benchmark (e.g. India, where lender rates span roughly 7%–12%+) are intentionally not shown.
We simulate both amortization schedules month-by-month:
Interest saved = baseline total interest − accelerated total interest. Time saved = baseline months − accelerated months. The opportunity-cost box grows your extra dollars at your chosen investment return so you can compare the two strategies apples-to-apples.
Every dollar above your scheduled payment reduces the loan balance directly. Because interest is charged on the remaining balance, cutting principal early saves compounded interest for the whole remaining term.
Paying half your monthly amount every two weeks results in 26 half-payments = 13 full payments per year — one extra. That alone typically cuts a 30-year loan by 4–6 years.
Compare your after-tax mortgage rate to your expected after-tax investment return. If investing wins by a comfortable margin AND you have emergency savings, invest. Otherwise the guaranteed return of paying down debt is hard to beat risk-adjusted.
Almost always yes for conforming loans, but note it explicitly ("apply to principal") on the payment or check. Some servicers otherwise prepay future payments instead.
Rare on modern conforming mortgages, but check your note. Some non-QM and older loans still have soft-prepay clauses.
No — it shortens the loan. Your required monthly stays the same until you request a recast (usually after a lump sum) which re-amortizes the lower balance over the remaining term.
Results are estimates for educational purposes only and are not financial advice. Verify with a qualified professional before making decisions.
Last updated October 2026