As ride-sharing startups have expanded their presence, residents in metropolitan areas across the country have signed up to drive, hoping to earn a steady supplemental -- or even primary -- income. But can they really count on it?

Different estimates disagree. Uber has said that the median wage for a New York City-based UberX driver working 40 hours a week is more than $90,000 a year. But using anecdotal evidence, Slate estimated that the figure is closer to $50,000.

NerdWallet, a startup that helps consumers with financial decisions, performed new calculations using data from SherpaShare, a service that helps drivers track ridesharing income and expenses. NerdWallet looked at the average fare for Uber, Lyft and Sidecar drivers and estimated how many trips a week drivers need to earn either $50,000, $75,000 or $100,000 annually.

"To make an annual income of $50,000, the average Uber driver needs to provide 60.21 rides each week, while those working for Lyft need to give 83.76 rides a week and Sidecar drivers would have to provide 72.03 rides in a week," NerdWallet reported on its website.

For a further breakdown of the company's results, check out the infographic below. 

 inline image