The unaudited figures show an increase from 78,000 "to in excess of 120,000" in paid-for digital-only subscriptions, based on the year ending 31 March 2012.
In November last year Journalism.co.uk reported that digital-only subscribers of the Economist had topped 100,000 for the first time.
And earlier this year digital editor for the Economist Tom Standage told the news:rewired conference that in two years time more than 70 per cent of subscribers to the Economist are expected to be reading the publication digitally.
The report adds that more than three times the number of print subscribers are now reading the title on a digital device weekly compared to the previous year, a trend the Economist says it expects to continue.
Digital editions of the Economist are available via iPhone, iPad and Android apps, as well as on Amazon’s Kindle and Fire devices, Barnes & Noble’s Nook and Zinio’s digital newsstand.
Managing director for digital at the Economist, Oscar Grut, said the past year had seen "the acceleration, if anything, of some game-changing trends in our market".
"More and more customers are looking to read magazine content on mobile reading devices; advertisers are spending more of their marketing budgets in digital channels (particularly on the web); and social media have become an increasingly important channel for readers to discover and engage with each other, with brands and with content.
"These trends present a great opportunity for the Economist".
He reports that joint circulation revenues for the Economist.com and digital editions have grown by 167 per cent year-on-year. Advertising revenues were said to be up 14 per cent.
Grut also outlines Economist.com's "significant progress" in community engagement.
"The number of unique visitors each month to Economist.com grew by an average of 40 per cent globally, while average monthly page views increased by 27 per cent year-on-year, exceeding 38 million in November 2011.
"Active participation also leapt with over 50,000 comments generated in March 2012 alone, 77 per cent more than last year. Engagement with our content in social media also continued its impressive upward trend with a community of over two million Twitter followers.
"Our priority has been, as ever, the reader proposition - to deliver The Economist to our readers in the most elegant and convenient way that we can, and to continue to grow (profitably) our overall circulation.
"But of course our circulation-led success also promises to translate into an increase in advertising, with a number of marquee brands already advertising in digital editions of The Economist.
"The Economist Group, like all publishers, faces market-changing reading and advertising trends; and, given the early success of digital editions of The Economist and the engaged community that we are building in and around Economist.com, we see a bright future ahead for The Economist."
Overall the Economist reported record operating profit of £67.3 million for the full year. Print advertising in the UK fell by 17 per cent while print circulation remained "steady".