New York: Indian Americans make calls to their families and friends back home for an average of three and a half hours in a month, more often on their mobile phones, the first ever study on their international communication habits has found.

The top five US cities from where calls to India originate are Princeton in New Jersey, San Francisco, Chicago, New York City and Dallas, says a statement from Rebtel, a global calling service for individuals and business based in Stockholm, which carried out the study.

Most-called cities

The top five most-called Indian cities are Hyderabad, Mumbai, Ahmedabad, Chennai and Bangalore. Kolkata and New Delhi come lower down the order.

Sunday, when the call rates are lower, is the most popular day for the Indian Americans to call home.

The study concludes that more Indian Americans are calling India more often due to lower costs, call quality improvements and cell phone access.

The study is based on Rebtel's calling volume from January to July this year.