Former first lady Michelle Obama has revealed details of her highly-anticipated memoir, which her publisher describes as “unusually intimate”.

Ms Obama announced in a Twitter post on Monday (AEDT) she “can’t wait” to share her upcoming tell-all, Becoming, chronicling the experiences that have shaped her.

“Writing BECOMING has been a deeply personal experience. I talk about my roots and how a girl from the South Side (Chicago) found her voice,” she tweeted.

She said she hopes her memoir, which will be available worldwide on November 13, “inspires readers to find the courage to become whoever they aspire to be”.

Writing BECOMING has been a deeply personal experience. I talk about my roots and how a girl from the South Side found her voice. I hope my journey inspires readers to find the courage to become whoever they aspire to be. I can't wait to share my story. https://t.co/d7DxEG85NK

— Michelle Obama (@MichelleObama) February 25, 2018

Penguin Random House chief executive Markus Dohle said in a statement the book will stretch the confines of a traditional former first-lady memoir.

“Becoming is an unusually intimate reckoning from a woman of soul and substance who has steadily defied expectations—and whose story inspires us to do the same,” it read.

The memoir was also described as “a work of deep reflection and mesmerising storytelling”.

“Warm, wise, and revelatory, Becoming is the deeply personal reckoning of a woman of soul and substance who has steadily defied expectations—and whose story inspires us to do the same,” Penguin Random House said in a statement.

Ms Obama will promote Becoming in an international book tour later this year, according to the publisher, and that one million copies of the book will be donated to the educational nonprofit program called First Book.

Mrs Obama and her husband, former President Barack Obama, last year reached a joint agreement with Penguin Random House for their respective books.

The deal is believed to be well in excess of $US30 million ($42 million).

Barack Obama, who has written the top sellers Dreams from My Father and The Audacity of Hope, has not yet scheduled the release of his memoir.