A minimum payment set as a percentage of the balance shrinks as the balance does, so the debt clears on a curve that flattens out — the last stretch is paid off at the floor amount, not at the percentage.

Years until the balance reaches zero139.56
Interest paid before the balance clears80,895.12
16.18Total interest measured against the amount originally owed
12
02550751000100200300400Interest charged in month one
Interest this monthPrincipal this monthPayment this month

While the minimum is still a percentage of the balance, the interest share of every payment is identical — both the charge and the payment scale with the same balance, so the ratio is fixed by the monthly rate against the minimum percentage. Principal only starts gaining ground once the payment hits the floor and stops shrinking.

02550751000100200300400Payment split evenly between interest and principalPrincipal's share in month one
Interest share pct

Interactive artifact by Delineo