Highest rate or smallest balance: which debt to clear first

The two payoff orders compared on total interest and on completion rate, and an honest answer about when the mathematically worse method is the right one.

The short answer: Two payoff orders compete once you have more than one debt. The avalanche pays the highest interest rate first and is mathematically optimal — it always costs less in total interest. The snowball pays the smallest balance first and finishes individual debts sooner, which produces visible progress and, for a lot of people, a higher chance of completing the plan at all. The honest recommendation is avalanche where the rate gap is wide, because the cost of the alternative is real money; snowball where the rates are similar, because then the difference in total interest is small and the difference in completion rate is not. Both beat paying minimums on everything.

Key points

Avalanche always costs less in interest; the only question is whether you will finish it.
Where the highest and lowest rates are close, the avalanche saving is small and the psychological argument wins.
A card at typical revolving rates outranks every other debt and almost every investment, so it comes first under either method.
Both methods depend on the same mechanic: pay minimums everywhere, and direct all spare money at exactly one debt.

The two orders

Both methods do the same thing mechanically: pay the minimum on everything, then send every spare rupee to one target debt. When that debt clears, its whole payment rolls into the next target. The methods differ only in how the target is chosen.

Avalanche and snowball, compared
	Avalanche	Snowball
Target	Highest interest rate first	Smallest balance first
Total interest paid	Lowest possible	Higher
First debt cleared	Later	Sooner
Argument for it	It costs less	It is more likely to be finished

The snowball is not a mathematical mistake made by people who cannot do arithmetic. It is a deliberate trade of some interest for a higher chance of completion, and whether that trade is good depends entirely on how much interest it costs — which is a number you can compute rather than argue about.

What the choice costs, worked

Three debts, ₹15,000 a month available above minimums

Card: ₹80,000 at ~3.2% a month
Personal loan: ₹1,80,000 at ~15% a year
Consumer durable loan: ₹35,000 at ~12% a year
Avalanche order: Card → personal loan → durable loan
Snowball order: Durable loan → card → personal loan
The cost of the difference: Months of card interest at over 3% a month, on ₹80,000

Here the rate gap is enormous — a card at roughly 3.2% a month is annualised well above 45%, against 12% for the smallest balance. Clearing the ₹35,000 first for the satisfaction costs several months of that. This is a case where avalanche is clearly right.

Reverse the example — three debts at 13%, 14% and 15% — and the avalanche advantage shrinks to a rounding error over a year. At that point the method you will actually finish is the better method, and there is no arithmetic argument against choosing it.

What to do before starting either

List every debt with its actual rate. Not the EMI, the rate. Card statements quote a monthly rate; annualise it before comparing with a loan.
Build a small buffer first. Around one month of essential expenses. Without it, the first unexpected bill goes back onto a card and the plan restarts — see emergency fund size.
Fix the leak. If the balance grew from ongoing overspending rather than a one-off, the payoff plan will be outrun by new borrowing. Tracking expenses comes first in that case.
Decide the monthly amount and automate it. A payoff plan that depends on remembering is a payoff plan that depends on a good month.

One habit makes either method dramatically more likely to finish, and it costs nothing: when a debt clears, do not let its payment disappear into general spending. The whole mechanic depends on the freed-up amount rolling into the next target, which is why the plan accelerates rather than staying flat — the amount going at the remaining debts grows every time one is cleared. Households that skip this find the last debt takes as long as the first, and conclude that the method does not work when what actually happened is that it was quietly switched off.

It is also worth writing down the projected finish date at the start, on the assumption you keep the current spare amount going. It converts an open-ended slog into a fixed term, which is psychologically a completely different thing — and it gives you something concrete to compare against when a windfall arrives and you are deciding whether to put it at the debt.

Budget Builder: Budget Builder separates minimum repayments (a need) from anything above the minimum (savings), which is the split that makes the spare amount visible.

Frequently asked questions

Which method should I actually use?

Compare the highest and lowest rates you hold. If the gap is wide — a card at revolving rates alongside a home loan — use avalanche, because the cost of doing otherwise is substantial and the highest-rate debt is also usually painful enough to stay motivating. If every debt is within a few percentage points, use whichever you will finish, which for most people is the snowball.

Should I pay off debt or invest?

Compare the debt's rate against the return you could reasonably expect after tax, and note that the debt return is certain while the investment return is not. Clearing a card balance is a guaranteed return at the card's rate, which no portfolio reliably matches. For a low-rate secured loan the comparison is genuinely close — [prepay or invest](/learn/loans/prepay-or-invest) works through it.

Does consolidating debt help?

Only if the new rate is genuinely lower after fees, and only if the behaviour that created the balance has changed. Consolidation that lowers the monthly payment by extending the term usually increases total interest, and a consolidation loan that leaves the cards open frequently ends with both the loan and fresh card balances. Check the total cost over the full term, not the monthly figure.