Compare paying off a loan with and without extra payments.
Adding extra to the standard payment pays down principal faster, reducing the months and interest. The comparison shows both how much sooner the debt ends and how much interest is saved. Even modest extra payments create outsized interest savings because they reduce the compounding base much earlier.
Debt Payoff Extra
Months = -ln(1 - r x B / P) / ln(1 + r); savings = interest without - interest with
Months = -ln(1 - r x B / P) / ln(1 + r); savings = interest without - interest with Adding extra to the standard payment pays down principal faster, reducing the months and interest. The comparison shows both how much sooner the debt ends and how much interest is saved.
Even modest extra payments create outsized interest savings because they reduce the compounding base much earlier.
This calculator takes 4 inputs: Balance, Annual rate, Original term years, Extra payment. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.