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Pay Off Mortgage or Invest Calculator
Pay off the mortgage, or invest the difference?
About this calculator
It is one of personal finance's great debates: prepay the mortgage for a guaranteed return, or invest for potentially more. This calculator models both paths over time — factoring in your mortgage rate, expected investment return, and taxes — so the tradeoff is grounded in numbers, not opinion.
What it shows you
- Net worth under "prepay" vs. "invest" over time
- The break-even investment return that makes investing win
- An after-tax comparison of both strategies
- Risk framing: guaranteed savings vs. variable returns
- The crossover year where one path overtakes the other
What you'll enter
- Loan balance, interest rate, and remaining term
- Current monthly payment
- Monthly amount to prepay or invest, plus any lump sum
- Expected annual market return
- Marginal tax bracket
When to use it
- Deciding where spare monthly cash should go
- Comparing a guaranteed rate against an expected market return
- Checking how your tax bracket shifts the answer
Why it matters
There is no universal right answer — it depends on rate, returns, and temperament. Modeling both honestly, instead of pushing one, is exactly the kind of advice that earns trust and referrals.
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