Calculating pi from coin flips (without randomness)

Happy Pi Day! The new value of pi is 3.2266. Pi-by-hand is happening - at some time in the future - at some location! Please opt-in for updates and tell us which places would work for you: https://docs.google.com/forms/d/e/1FAIpQLScprg57Bvv1jOfoMQwriHPegTnCjik2p9xrly0zQ84ANYMfEQ/viewform?usp=dialog Huge thanks to Jim Propp for discovering this amazing bit of maths. For more math details: https://arxiv.org/abs/2602.14487 For the backstory: https://mathenchant.wordpress.com/2026/03/12/in-praise-of-stupid-questions/ Check out Sophie Maclean's Numberphile video: https://www.youtube.com/watch?v=fczN0BCx0xs My coin flip data is available here: https://www.dropbox.com/scl/fi/y7pueeebnt2v4i2w8sfz1/coinflip-stats.xlsx?rlkey=n9s1onlj9l6xebl1vuygl3u4l&st=4axban7n&dl=0 Huge thanks to my Patreon supporters. They are flipping brilliant. http://patreon.com/standupmaths CORRECTIONS Nothing yet. Let me know if you spot anything! Filming and editing by Alex Genn-Bash Written and performed by Matt Parker Produced by Nicole Jacobus Content wrangling by Rhys Jones Music by Howard Carter Design by Simon Wright and Adam Robinson MATT PARKER: Stand-up Mathematician Website: http://standupmaths.com/