Interpretation
The lowest-interest result is not the only consideration.
Highest-interest-first generally minimizes modeled interest. Smallest-balance-first may produce an earlier account payoff, which some people find easier to sustain.
Debt calculator
Compare debt snowball and highest-interest-first payoff orders while holding the same monthly payment constant. See estimated payoff time, interest and when each balance would clear—not a personalised repayment recommendation.
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Method
Each month, the model adds balance × APR ÷ 12, pays each required minimum and directs the rest of the fixed payment budget to the next target. When a balance reaches zero, its former minimum rolls forward. The milestone lists show the modeled month in which each entered balance clears.
Interpretation
Highest-interest-first generally minimizes modeled interest. Smallest-balance-first may produce an earlier account payoff, which some people find easier to sustain.
Source
The US Consumer Financial Protection Bureau describes paying either the smallest debt first or the debt with the highest interest rate first, including the tradeoff between motivation and total cost.
Consumer Financial Protection Bureau — How to reduce your debt