How many decimals of pi do we need? (2016)
Summarized answer from the article.<p>> For JPL's highest accuracy calculations, which are for interplanetary navigation, we use 3.141592653589793<p>> by cutting pi off at the 15th decimal point… our calculated circumference of the 25 billion mile diameter circle would be wrong by 1.5 inches.<p>The author also has a fun explanation that you don’t need many more digits to reduce the error to the width of a hydrogen atom… at the scale of the visible universe!