Snowball or avalanche?
The avalanche method pays the minimum on everything and puts every extra dollar toward the debt with the highest interest rate. It always costs the least in interest.
The snowball method puts the extra toward the smallest balance first. You pay off whole accounts sooner, and many people find those early wins keep them going. The calculator shows what the difference costs, so you can decide whether the motivation is worth it.
Why the extra payment matters so much
When a debt is paid off, its minimum payment doesn’t disappear: it rolls onto the next debt. That roll-over, plus whatever extra you add, is what makes a plan finish years earlier than paying minimums alone.
How this calculator works
Each month, interest is added at your APR divided by 12, every debt gets its minimum, and everything left goes to the debt your strategy ranks first. It’s the same math the Pennyjay app uses.