The trend is indicative of the growing use of mobile devices.
Mayer spoke at the TechCrunch Disrupt conference, being held this week in New York, where she was interviewed by TechCrunch founder Michael Arrington.
As head of location and local services, Mayer oversees the company's geospatial offerings such as Google Maps.
The Google Maps app has been installed on 200 million mobile devices, Mayer said. People use the app to get directions to a desired location, as well as to orient themselves with their surroundings.
And, increasingly, they are carrying out these tasks on mobile devices, while they are on the move, rather than consulting the service on their desktop computers before they venture out.
Right now, about 40 percent of all map-related searches that come into Google come from mobile devices. "That is really high," she noted. On weekends, that percentage climbs to over 50 percent. The company expects that the percentage of mobile-based searches will become dominant within the next month or so, Mayer said. "It will cross permanently in June," she predicted.
Mayer also oversees Google Places, which allows users to rate retail establishments. She noted that around 20 percent of all Google searches are for places that are local to the user. With mobile phones, these local searches can run as high as 40 percent.
Despite Arrington's insistent questioning, Mayer would not reveal what percentage of Google searches overall came from mobile devices. The company does not release those numbers, she said.
