Julia EvansApr 13, 2023

today I'm thinking about the "don't use floating point for money" advice I hear all the time. It obviously has a lot of truth to it.

But -- Excel/Google Sheets uses floating point for all of its calculations, people use spreadsheets for money calculations all the time, and it generally seems to work just fine -- the results get rounded for display.

So I'm trying to figure out if there's a more nuanced guideline than "never use floating point for money".

Show threadBoba YagaApr 13, 2023
@b0rk I would guess Excel is using base-10 floats and not base-2, which goes a long way to help.
Show threadRichard Barrell

@bobayaga @b0rk last I checked nah, Excel is using ieee754 doubles.

I think one small factor is that financial *forecasting* just isn't really very precise in the first place. Small factor because forecasting isn't the main use of Excel, even though as I understand it that's what Excel was originally intended for.

Bigger factor may be that nobody actually really cares about single penny rounding errors. They're nothing compared to shrinkage.

Apr 13, 2023 at 6:25pmWeb