How much of a difference does paying twice the minimum on my credit card really make?

An enormous one. Minimum payments are usually calculated as roughly 1% to 3% of the balance plus interest, deliberately low so the balance and interest linger for years. On a $5,000 balance at 22% APR, paying only the minimum can take well over a decade and cost more in interest than the original debt.

Doubling the payment can cut the payoff time to a fraction of that and slash total interest dramatically, because more of each payment attacks principal instead of interest. Even a fixed extra $50 or $100 a month, rather than a shrinking minimum, changes the outcome. The CARD Act requires issuers to print a 'minimum payment warning' box on your statement showing how long minimums take. See your own numbers at wealthserene.com/tools/debt-payoff.