The i launched in October last year as a 20p digest paper and the sister title to the Independent and Independent on Sunday.
Executives at the i will be hoping the new data, out today (14 July), will bolster its status in the eyes of media agencies and advertisers.
The data estimated the paper attracted 368,000 readers a day between November 2010 and May 2011. In a breakdown of the data, 203,000 of its readers are men and 165,000 women.
The bulk, 268,000, are ABC1 social grade and well over half, 223,000, are over 45-years old.
In May this year, the i reported an Audit Bureau of Circulations (ABCs) figure of 167,067, up nearly 6,000 readers on the previous month.
Unlike the Audit Bureau of Circulations (ABCs) figures, which report the number of papers sold, the NRS canvasses over 36,000 people to find out how many readers newspapers have.
The title was supported by TV advertising earlier this year, and is now edited by Stefano Hatfield, who replaced Simon Kelner.
There is no like-for-like data to compare it with.
The now-defunct afternoon freesheet thelondonpaper reported a debut NRS of 713,713, on a distribution of around 500,000.
Its rival, the London Lite, reported a first NRS figure of 745,000 on a distribution of around 400,000.
The London Evening Standard's debut NRS following its move to a free sheet was 1.348 million, on a distribution of around 500,000.
Jon O'Donnell, group commercial director, said: "Considering we’re a newspaper that's only nine months old it's fantastic that the NRS has been able to provide us with an early sighting of our readership. It’s clearly early days but it looks hugely encouraging."