Converting to Active Dry Yeast from Instant Dry Yeast

[Citrus]

I usually use 5 grams of instant dry yeast for 500 grams of bread flour, but since I read here it's better to use active dry yeast, I wonder how much should I put? Oh and this is for doughnut dough.

 

[Laurence]

Different pundits - different views on how active 'active dry' is compared with 'instant' yeast, but equally it depends on which manufacturer you are going to use and the one you are currently using.
As a round figure, you might try adding 30-50% more for 'active dry' but it is, frankly, a moving target.
I would stay on the side of less rather than more - in my experience with Dove's Farm 'instant' (sold as 'quick') 1% is on the high side - I use 0.85% (about 4.5g for 500g flour) but I've also used supermarket 'instant' and that can behave in a very similar way to other brands' 'active dry', i.e. there is no evidence of standard activity per gram.
Is 'instant' better than 'active dry'? I've tried both and compared with fresh yeast and, provided you have got the correct level of yeast - there's no difference in taste or texture (unless the fresh yeast is old when the dough can be flabby).
I'd suggest you try you do some tests and let us all know how you get on.
Happy baking!