In Chapter 5, you’ll see how compounding can turn small, consistent
savings into serious wealth over time. It’s one of the most encouraging
ideas in personal finance.
Debt is that same force — pointed at you instead of for you.
The Same Math, Flipped
Compounding doesn’t care whether it’s working for you or against you.
It’s just math: a percentage, applied repeatedly, growing on top of
itself. When you save and invest, that math builds your wealth. When you
carry high-interest debt, that exact same math builds what you owe —
often faster than you think, because consumer debt interest rates tend
to be much higher than investment returns.
A savings account might earn you a modest single-digit return. A
high-interest investment might average around 7–10% a year over the long
run. Meanwhile, credit cards and many personal loans charge interest
well into the 20%+ range annually. That gap is the whole problem:
you cannot out-save or out-invest debt that’s growing faster
than your money can grow.
This is why Chapter 3 put debt payoff before serious investing.
Paying off a debt charging 25% interest is, mathematically, the same as
finding an investment that guarantees you a 25% return. No investment in
this book — or anywhere reputable — can promise that. Debt payoff is
often the best “return” available to you.
Not All Debt Is the Same
This chapter isn’t telling you all debt is evil. There’s an important
distinction:
High-interest, consumer debt (credit cards, payday
loans, most personal loans, “buy now pay later” schemes): This is the
debt working against you the hardest. It typically funds depreciating
purchases — things that lose value or are already gone by the time
you’re still paying for them.
Lower-interest, asset-backed debt (a mortgage,
sometimes a car loan, a business loan tied to income-generating assets):
This debt can be reasonable, sometimes even strategic, especially if the
interest rate is low and the debt is attached to something building
value or generating income.
The rule of thumb: if the interest rate on a debt is higher than what
you could reasonably expect to earn investing, it’s a priority to
eliminate. If it’s lower, it may be fine to pay down steadily while you
also invest.
Two Ways to Pay It Off
There are two well-known strategies, and the “right” one depends more
on your psychology than your math.
The Avalanche Method (mathematically optimal): List
all debts by interest rate, highest to lowest. Pay minimums on
everything, then throw every spare unit of money at the highest-interest
debt first. Once it’s gone, roll that payment into the next highest.
This saves you the most money in total interest.
The Snowball Method (psychologically optimal for
many people): List all debts by balance, smallest to largest, regardless
of interest rate. Pay off the smallest balance first for a quick win,
then roll that payment into the next smallest. This costs slightly more
in total interest, but the early wins build momentum — and for many
people, that momentum is what actually gets the debt paid off.
Neither is wrong. If you tend to stick with a plan once you see
progress, snowball may serve you better even though it’s not the
“optimal” spreadsheet answer. If you’re driven purely by numbers,
avalanche will save you more.
Breaking the Cycle, Not
Just the Balance
Paying off debt without changing the habits that created it just
resets the clock. Before or while you pay debt down:
- Identify what caused it (irregular income, no emergency fund, one
significant event, ongoing overspending) — the cause changes the
fix - If it was a lack of buffer, revisit Chapter 3 once the
highest-interest debt is cleared - If it was ongoing overspending, revisit your savings rate
calculation from Chapter 2 — the same tracking that reveals your savings
rate will also reveal where debt is quietly forming
The Turning Point
There’s a specific moment in this process worth naming: the day your
monthly debt payments equal zero, and that same amount of money is
suddenly available to save and invest instead.
This is often the single biggest jump in someone’s savings rate in
this entire book — bigger than any budgeting tip. Getting there is the
whole point of this chapter.