With the MTA fare hike—up to $2.75 for a single ride—set to snatch our spare quarters on Sunday, straphangers have been wondering how to prevent their loose change from being held hostage on a magnetic strip, thanks to those tricky 11 percent bonuses and preset refill amounts.

For those magic numbers, you can peruse this chart that took three people in our office to put together, OR you can use this handy online calculator the MTA made for us, which...seems to agree with our math! Who says bloggers can't do anything right?

The calculator will tell you how many rides you can get out of whatever amount you're sticking on your card, whether you're refilling or purchasing a new card—it'll also calculate the balance for you. If you'll be stuck with a remainder, the calculator will also suggest some amounts you can use to score a balance of $0.

Note that the MTA made $200 million off expired and unused MetroCard cash back in 2010, so they're being quite kind by offering such a convenient tool to save you money. Don't tell the tourists.