Update at 7:04 p.m. Pacific: Updated with founders’ info, how Up Hail is getting its rates, and its future plans.  

Since we know you’ve long been wondering which ride-sharing service, Lyft or UberX, is cheapest — and since their rates fluctuate all the time due to “surge pricing” and other factors — we give you Up Hail, a service that calculates ride prices in real-time.

UpHail is as simple as you’d want it to be: Enter your origin and your destination, press the button, and voilá: Up Hail lets you know how much, approximately, your ride will cost with each of these two major ride-sharing services. It appears to use real-time data, and shows you a surge fare map, as well as the surge rate of its results when applicable. Up Hail seems to be available across the U.S., wherever the ride-sharing services are available.

Here’s an example, I looked up the fair from the Embarcadero BART station to the San Francisco Caltrain station:

Up Hail

Up Hail co-founder Avi Wilensky said in an email that Up Hail began when Uber opened up its API in August, and he decided to write a script to monitor surge price activity alongside weather conditions in Manhattan. From there, he co-founder Josh Delman eventually worked up to showing both Lyft and UberX pricing side-by-side.

As mentioned, the site uses Uber’s newly available API (Uber has even helped with making sure it was applied accurately), and calculates the Lyft rates by using Google Maps and region-specific fare formulas Lyft does make available since it doesn’t have a public API.

It’s not really clear yet what will happen to it given both Uber and Lyft’s reactions to the now pivoted and acquired Corral Rides. In the spring of 2013, Corral Rides tried to help ride-sharing passenger by aggregating the different services into one app, though it didn’t last long before Lyft yanked its data out of the app, and Uber revoked Corral Rides’ ability to hail its cars.

Although Uber is cooperating with Up Hail since it has a public API, the duo is still concerned about whether “displaying competitor information alongside their data may not be in compliance with their API terms,” as Wilensky wrote in an email to VentureBeat.

Wilensky also said that they’re considering eliminating the fare comparison feature as they’ve found that users, though he didn’t specify where exactly, tend to take Uber except when there is surge pricing, and the surge pricing maps seem to be the more useful feature for their users. As a San Francisco resident who uses both more or less equally, I’d recommend they keep it.

Up Hail doesn’t include ride-sharing service SideCar, likely because of SideCar’s model, which lets drivers and passengers agree on a price, rather than relying on a standardized fare set by the company.

The service seems to have popped up about a month ago, given the Sept. 15 date on its first blog entry, and says it plans to cover Canada, South America, Europe, and Australia “very soon.”

“For now we focusing on the user experience and building a useful product; we will figure out the monetization part somewhere down the road,” wrote Wilensky.

Up Hail was created by Avi Wilensky and Josh Delman, who currently work together at Promedia Corp., a New York City-based web dev and SEO shop.