Extra $300/Month on a $350,000 Mortgage (15-Year)
See how much faster you pay off a $350,000 15-year mortgage when adding $300 extra per month at 6.5%.
How to use this tool
- Enter mortgage balance, annual interest rate, remaining term and extra monthly payment in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your interest saved and the full breakdown beneath it.
Adding $300 per month to a 15-year $350,000 mortgage can shave years off the loan and save substantial interest.
Frequently asked questions
- Should I pay extra principal or invest the money?
- It depends on your mortgage rate vs. expected investment return. If your mortgage rate is higher than after-tax investment returns, paying down debt is the better risk-adjusted move.
- How do I make sure extra payments reduce principal?
- Tell your lender to apply any extra amount to principal, not the next month's payment. Most servicers allow this online or by note on a check.