Original research

Each study here is a question put to the payoff engine rather than an opinion about debt. The portfolios are synthetic, the method is written down, and every study ships the dataset it was computed from as a spreadsheet you can open and check.

None of this is advice about your own debts, and none of it is a claim about what borrowers actually owe. It is what the arithmetic returns for a declared set of assumptions — which is why the assumptions are on every page, above the limits.

• What the snowball order actually costs

  Both payoff orders run over a large synthetic corpus, with the corpus published.

• What an extra payment actually buys

  Levels of extra monthly payment, each measured against the same baseline.

• Where a minimum payment stops working

  What an opening minimum does to a balance, swept across both common issuer rules.

• What a penalty-adjacent rate costs

  The same balance and the same payment, at an ordinary rate against a penalty-adjacent rate.

• When the cheaper order is barely cheaper

  The same corpus, segmented by how far apart each portfolio's rates are.

Related

• Payoff calculators
• Comparisons
• Understanding debt payoff
• Methodology