Daniel Tammet was born in a working-class suburb of London, England, on 31 January 1979, the eldest of nine children. His mother had worked as a secretarial assistant; his father was employed at a sheet metal factory. Both became full-time parents.
Despite early childhood epileptic seizures and atypical behaviour, Tammet received a standard education at local schools. His learning was enriched by an early passion for reading. He won the town's 'Eager Reader' prize at the age of eleven. At secondary school he was twice named Student of the Year. He matriculated in 1995 and completed his Advanced level studies (in French, German, and History) two years later.
In 1998 Tammet took up a volunteer English teaching post in Kaunas, Lithuania, returning to London the following year. In 2002 he launched the online language learning company Optimnem. It was named a member of the UK's 'National Grid for Learning' in 2006.
In 2004, Tammet was finally able to put a name to his difference when he was diagnosed with high-functioning autistic savant syndrome by Professor Simon Baron-Cohen at Cambridge University's Autism Research Centre.
The same year, on March 14, Tammet came to public attention when he recited the mathematical constant Pi (3.141...) from memory to 22,514 decimal places in 5 hours, 9 minutes, without error. The recitation, at the Museum of the History of Science in Oxford, set a European record.
Tammet began writing in 2005. His first book, Born On A Blue Day, subtitled 'A Memoir of Asperger's and an Extraordinary Mind', was first published in the UK in 2006 and became a Sunday Times bestseller. The US edition, published in 2007, spent 8 weeks on the New York Times bestseller list. In 2008, the American Library Association named it a 'Best Book for Young Adults'. It was also a Booklist Editors' Choice. It has sold over 500,000 copies worldwide, and been translated into more than 20 languages.
In 2009, Tammet published Embracing the Wide Sky, a personal survey of current neuroscience. The French edition (co-translated by Tammet himself) became one of the country's best-selling non-fiction books of the year. It also appeared on bestseller lists in the UK, Canada, and Germany, and has been translated into numerous languages.
Thinking in Numbers, Tammet's first collection of essays, is published in August 2012.
In 2008 Tammet emigrated to France. He lives in Paris.