Einstein’s Equation for Success in Life: A=X+Y+Z

Albert Einstein? Apocryphal?

Dear Quote Investigator: Einstein famously constructed a foundational equation about energy: E = mc². Apparently, he also fashioned a less-well-known humorous formula about success in life using the terms A, X, Y, and Z. Did Einstein actually craft this quasi-mathematical joke?

Quote Investigator: In 1929 Albert Einstein was interviewed by Samuel J. Woolf in Berlin for a piece published in “The New York Times Magazine”. The following passage appeared at the end of the article. Emphasis added to excerpts by QI: 1

It was time for me to go and as he saw me to the door I asked him what he considered the best formula for success in life. He smiled, that same awkward bashful smile and thought for a minute.

“If A is success in life,” he replied, “I should say the formula is A=X+Y+Z, X being work and Y being play.” “And what,” I asked, “is Z?”

“That,” he answered, “is keeping your mouth shut.”

Below are additional selected citations in chronological order.

The article in “The New York Times” appeared in August, and the formula was reprinted in “The Sydney Morning Herald” in December of 1929. The reporter interleaved his own commentary: 2

In this equation, as Einstein explained to the interviewer, “X” means work. Without work, and hard work, success is impossible. “Y,” the second factor of success, is play. This is equally necessary, because it is a condition of efficiency in work. “All work and no play makes Jack a dull boy,” though in these days of decreasing hours of labour it is not easy to find Jack!

“And what is ‘Z,'” inquired the interviewer of Einstein. “That,” he answered, “is keeping your mouth shut.” There is a truth in this simple formula that deserves attention.

In 1932 a newspaper in Charleston, West Virginia printed a condensed version of the remark without the equation: 3

The formula for success in life is work, play and keep your mouth shut. —Albert Einstein, scientist.

In 1943 the comment continued to circulate in ‘The Wall Street Journal” humor column called “Pepper and Salt”. The item was titled “The Saving Ingredient”, and the equation letters were not capitalized: 4

Professor Albert Einstein, in the course of a newspaper interview, offered his idea of success in life in the following formula: “If a is success in life, I should say that the formula is a equals x plus y plus z, x being work and y being play.”

“And what is z?” asked the reporter.

“That,” replied the great scientist, with a laugh, “is keeping your mouth shut.”

In 2010 “The Ultimate Quotable Einstein” edited by Alice Calaprice included the remark and pointed to the 1929 interview in “The New York Times”. 5

In conclusion, Albert Einstein employed a mathematical format to make a joke about success in life that was recorded in the August 1929 citation given above.

(Great thanks to anonymous individual who was confident that this was an apocryphal quotation. This inquiry led QI to formulate this question and perform this exploration.)


  1. 1929 August 18, New York Times, Section 5: The New York Times Magazine, Einstein’s Own Corner of Space by S. J. Woolf, Start Page SM1, Quote Page SM2, Column 5, New York. (ProQuest)
  2. 1929 December 28, The Sydney Morning Herald, Success in Life: Einstein’s Formula by R.A. Thompson, Quote Page 5, Column 2, Sydney, New South Wales, Australia. (Newspapers_com)
  3. 1932 July 25, The Charleston Daily Mail, “Remarkable Remarks”, Quote Page 4, Column 4, Charleston, West Virginia. (Newspapers_com)
  4. 1943 February 18, Wall Street Journal, Pepper and Salt, Quote Page 6, Column 2, New York. (ProQuest)
  5. 2010, The Ultimate Quotable Einstein, Edited by Alice Calaprice, Section: On Life, Quote Page 230, Princeton University Press, Princeton, New Jersey. (Verified on paper)