NEW YORK (MainStreet) — Largely unregulated, prepaid debit cards can be notoriously hard to compare because fee structures often differ from provider to provider and consumer to consumer, depending on how the card is being used.

Luckily, finding out how much a prepaid product will cost you just got a bit easier, thanks to the folks over at NerdWallet.

The credit card ranking site launched a tool on Tuesday that allows consumers to compare and contrast prepaid debit cards currently on the market.

The tool asks users to specify whether they plan on linking direct deposit to the card and withdrawing money from ATMs, as well as how often they will be reloading funds on the product. It then calculates the actual cost of the product based on these preferences, and ranks the best cards based on which offer the most cost-effective fee structure.

The tool also gives users the opportunity to compare the costs of these cards to basic checking account options. Users can specify how often they overdraft their account, how often they use checking cashing services and how much they pay to cash their checks in order to determine if prepaid cards are a more affordable option. (According to NerdWallet, they rarely come out on top.)

“To ensure that consumers are treated fairly, we provide them with the best information possible and help them easily distinguish which card is best for their lifestyle, not the card issuer’s bottom line,” NerdWallet CEO Tim Chen said in a written statement.

How can you minimize the amount of fees incurred when using a prepaid product? Find out in the MainStreet article “The Right Ways to Use a Prepaid Card.”

—Jeanine Skowronski is staff reporter for MainStreet. You can reach her by email at Skowronski.jeanine@thestreet.com, or follow her on Twitter at @JeanineSko.