Comparison explorer
Pay off debt or invest?
There is no single rate where this flips for everyone. Move the rate and watch the case weaken, tie, then reverse — against a range of expected returns rather than one number.
The shaded band is our expected investment return after costs: 3.6% to 8.6% a year. Inside it, the two sides are close. There is no single crossover rate.
At 9%, the certain saving is above the whole return range
Paying this down saves 9% a year with certainty. After costs, our expected range for a diversified portfolio is 3.6%–8.6% a year, and even the top of that is uncertain. On these assumptions the debt side is stronger.
- Money used to pay debt is hard to get back. Money in a brokerage stays available — worth something when the comparison is close.
Paying down a loan produces a guaranteed interest saving equal to its rate. Investing produces an expected return — a range of outcomes, not a number. The same portfolio that averages a middling return over decades regularly loses money over single years, and the shorter your horizon, the more that matters.
So the comparison here is a guaranteed saving against a band. Above the band, the certain side is stronger. Below it, the expected edge favours investing. Inside it, the arithmetic does not separate them and the tiebreakers are yours: liquidity, certainty, and how you would behave in a bad year.
Two things sit above this decision either way — making every minimum payment, and capturing an employer match if you have one.
This is one decision. See the whole picture.
The same engine runs a short guided journey that puts this decision in order against everything else competing for the money.
Common questions
Where these figures come from
2026 figures · checked 2026-08-18- Federal ReserveFederal Reserve — H.15 selected interest ratesPrime rate and other reference rates used in the explorers
- Federal Student AidFederal Student Aid — Student loan forgivenessPSLF, income-driven repayment forgiveness and related programs
Statutory limits are taken from these publications. Economic assumptions — expected returns, emergency-fund targets — are ours, are shown wherever they are used, and are not sourced from anyone.
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When rates move, the line between paying down debt and investing moves with them. We'll tell you when it does.
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