Card interest is charged monthly on whatever balance remains. With $5,000 at 22% APR, interest alone adds about $92 a month. A payment of $90 feels like progress but never touches the balance at all - you could pay it for decades and still owe $5,000.
Now look at real progress. Pay $200 a month on that same card and you are done in 34 months, for about $1,750 in interest. Drop to $150 and it stretches to 52 months and $2,798 in interest. The extra $50 a month saves you roughly $1,050 and a year and a half of payments.
The calculator assumes a fixed monthly payment, no new purchases on the card, and no fees. Real minimum payments shrink as the balance falls, which is exactly why they take so long - most of each one goes to interest, not principal. If your card issuer charges an annual fee or you keep spending on the card, the real payoff takes longer.
Estimates only. Your statement's own payoff box shows the issuer's math for your account.