Britney Gallivan - wikipedia Britney Gallivan Britney Crystal Gallivan ( born 1985 ) of Pomona, California, is best known for determining the maximum number of times that paper or other materials can be folded in half. Contents 1 Biography 2 Paper folding theorem 3 In popular culture 4 See also 5 References 6 Further reading 7 External links Biography In January 2002, while a junior in high school, Gallivan demonstrated that a single piece of toilet paper 4000 ft ( 1200 m ) in length can be folded in half twelve times. This was contrary to the popular conception that the maximum number of times any piece of paper could be folded in half was seven. She calculated that, instead of folding in half every other direction, the least volume of paper to get 12 folds would be to fold in the same direction, using a very long sheet of paper. A special kind of $85 - per - roll toilet paper in a set of six met her length requirement. Not only did she provide the empirical proof, but she also derived an equation that yielded the width of paper or length of paper necessary to fold a piece of paper of thickness t any n number of times. She was a keynote speaker at the September 22, 2006, National Council of Teachers of Mathematics convention. In 2007, Gallivan graduated from University of California, Berkeley with a degree in Environmental Science from the College of Natural Resources. Paper folding theorem Further information : Mathematics of paper folding For single - direction folding ( using a long strip of paper ), the exact required strip length L is L = π t 6 ( 2 n + 4 ) ( 2 n − 1 ), ( displaystyle L = ( \frac ( pi t ) ( 6 ) ) left ( 2 ^ ( n ) + 4 \right ) left ( 2 ^ ( n ) - 1 \right ), ) where t represents the thickness of the material to be folded, L is the length of a paper piece to be folded in only one direction, and n represents the number of folds desired. An upper bound and a close approximation of the actual paper width needed for alternate - direction folding is W = π t 2 ( 3 / 2 ) ( n − 1 ), ( displaystyle W = pi t2 ^ ( ( 3 / 2 ) left ( n - 1 \right ) ), ) where W is the width of a square piece of paper with a thickness of t, and n is the desired number of folds to be carried out in alternate directions. For paper that is not square, e.g., having a 2 : 1 ratio, the above equation still gives an accurate limit. In popular culture Gallivan 's story was mentioned in the episode `` Identity Crisis '' of Numb3rs, she served as a consultant and was mentioned in an episode of MythBusters on the Discovery Channel in 2007, and in episode 3 of QI 's F series. See also Mathematics of paper folding Origami Recreational mathematics References Jump up ^ Korpal, Gaurish ( Nov 25, 2015 ). `` Folding Paper in Half ''. At Right Angles. 4 ( 3 ) : 20 -- 23. Jump up ^ Folding Paper in Half 12 Times Archived 2005 - 11 - 02 at the Wayback Machine. Jump up ^ Annotated Mythbusters Further reading Clifford A. Pickover, The Math Book ( Stirling, New York, 2009 ) p. 504 External links Folding Paper in Half 12 Times ( Historical Society of Pomona Valley ) at the Wayback Machine ( archived January 19, 2017 ) Folding at MathWorld `` Sloane 's A076024 : Loss function for folding paper in half ''. The On - Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Britney_Gallivan&oldid=801403989 '' Categories : 1985 births Living people Paper folding University of California, Berkeley alumni People from Pomona, California Hidden categories : Webarchive template wayback links Wikipedia articles needing clarification from November 2015 Talk Contents About Wikipedia Español עברית Română Edit links This page was last edited on 19 September 2017, at 13 : 21. About Wikipedia

Question: a paper can be folded how many times
Answer: twelve