Should you pay off a 7% mortgage or invest?
With a 7% mortgage and a 7% expected investment return, investing the extra money ends roughly $13,588 ahead after 30 years. But that's only the math on averages — paying off a mortgage is a guaranteed return and buys real peace of mind.
Why the mortgage rate decides it
Paying off a mortgage is a guaranteed return equal to the mortgage rate. Investing is an expected return with risk. So the comparison is simply 7% guaranteed vs ~7% (risky) expected:
- When the mortgage rate is well below your expected return (like 7% vs 7%), investing usually wins on average — your money compounds faster than the loan costs.
- When the mortgage rate approaches or exceeds your expected return, paying it off wins — and it's a certain win, with no market risk.
- Guaranteed vs risky matters. A paid-off house lowers your fixed costs and sequence-of-returns risk in retirement. Many people rationally choose the guaranteed return even when investing edges it out on paper.
Before you decide
A few things this comparison assumes you've already handled: capturing your full 401(k) match (an instant ~100% return that beats both), paying off any high-interest debt (credit cards dwarf a mortgage rate), and keeping an emergency fund. Money locked in home equity is hard to access without a sale or a HELOC — so don't pay down the mortgage with money you might need.
Assumptions: $450k home, 20% down, 30-yr term, an extra $12,000/yr toward principal, 7% investment return, 3% inflation, single filer. Mortgage interest is only deductible if you itemize — most people take the standard deduction, so this treats it as non-deductible. Model your own numbers in the calculator.
A high rate today is not necessarily a high rate forever
A fixed mortgage at a rate this high carries a hidden feature: if rates fall later you can refinance to the lower one, but you can never be forced to refinance up. That built-in option to reset the rate downward — while keeping the right to hold your rate if rates rise — is worth remembering before pouring surplus into principal.
The tension is real. Prepaying earns a guaranteed return at today's rate, which is genuinely attractive. But it is also irreversible and illiquid: money sent to principal is sealed in the walls, retrievable only by selling or borrowing against the home. Cash kept liquid preserves flexibility — to invest, to refinance, or simply to cover an emergency.
- Prepaying now locks in a strong guaranteed return but forfeits liquidity.
- Waiting keeps your options open, including a future refinance if rates drop.
A middle path often fits: keep an ample cash reserve and a funded match, then steer extra toward principal. If rates later fall, refinancing shrinks the payment; if they do not, the prepayment was still a fine guaranteed return.
Common questions
Should I pay off a 7% mortgage or invest?
On average, investing wins by about $13,588 over 30 years because a 7% expected return beats the 7% guaranteed by paying it off. But paying off is guaranteed and risk-free, which many people rationally prefer.
Is it worth paying off my mortgage early?
Financially it's worth it when your mortgage rate is at or above your expected after-tax investment return. Below that, investing usually builds more wealth — though a paid-off home reduces risk and fixed costs, which has real value beyond the math.
What should I do before paying extra on my mortgage?
Capture your full 401(k) match, clear high-interest debt (credit cards), and hold an emergency fund first — each of those beats extra mortgage payments. Only then does paying down a low-rate mortgage compete with investing.