If I’m reaching for calculator, I’m reaching for my phone.

At that point I’m either using the stock iOS calculator or iHP48, HP48 clone.

It mostly depends on which page of apps I’m on and which is closest.

I like the unit conversion on the iOS calculator, easier to use for trivial calcs than the HP.

Biggest gripe on iOS is a single memory. On the HP I’m mostly hooked on the infinite stack, and that’s why I use it over the HP-42 clone app I have as well.