[bitmedley]

Excel uses IEEE 754 double precision which stores up to 17 significant digits but the Excel UI itself only displays up to 15 significant digits.

[0] https://en.wikipedia.org/wiki/Double-precision_floating-poin.... [1] https://www.mrexcel.com/excel-tips/17-or-15-digits-of-precis... [2] https://www.youtube.com/watch?v=WZfjmbEDbfI