A fixed-rate mortgage is one of the few positions where inflation works for you rather than against you. You borrowed today's dollars and repay in tomorrow's cheaper ones. If your rate is 3 or 4% while inflation runs at 4 or 5, the real cost of that debt is negative — you're being paid to hold it.
The nominal balance is what the bank statement says. The real balance is what it's actually worth in purchasing power.
Each year, inflation erodes the real value of what you owe. That erosion is a transfer from the lender to you.
A genuinely counter-intuitive idea, and one of the few places where inflation is on your side.
You borrowed money in today's dollars. You repay it in future dollars, which buy less. If your mortgage is fixed at 3.6% while prices rise 4% a year, the debt is shrinking in real terms faster than the interest is accumulating — the real interest rate is negative, and in purchasing-power terms the lender is effectively paying you to hold the loan.
This isn't a trick. It's why fixed-rate borrowers did well through the inflationary 1970s, and why a mortgage taken at 2.5% in 2021 looked considerably better by 2023.
Ruth owes $280,000 at 3.6% fixed, with 18 years to run and a repayment of $1,763 a month. Inflation is running at 4%.
Her real interest rate is about −0.4%. In year one the bank charges her roughly $10,000 in interest, while inflation quietly erases about $11,200 of the debt's real value — so she's marginally ahead before making a single extra payment.
Ten years in, the statement will say she owes around $146,900. In today's purchasing power that's closer to $99,200. The $47,700 difference is debt that inflation quietly dissolved, and nobody sends a statement for it.
Her repayment is fixed at $1,763 for the whole term. If her pension indexes with inflation, that payment takes a smaller bite every single year. That's the real benefit — not a windfall, but a bill that shrinks while everything else grows.
This is an argument for not rushing to repay debt you already have at a low fixed rate. It is not an argument for taking on new debt — new borrowing happens at today's rates, which reflect today's inflation expectations.
The practical upshot: if you have a cheap fixed mortgage and you're wondering whether to clear it early, the real cost of carrying it may be far lower than the headline rate suggests. Worth weighing before you commit the cash.
General information only — not financial advice. Inflation is assumed constant, which it is not; the whole argument here depends on inflation staying above your fixed rate, and it has historically spent long stretches below it. A negative real rate on debt does not put cash in your pocket — it reduces a future obligation, which is only useful if you can service the payments today. Anyone on a variable rate should treat this as an illustration rather than a strategy.