Milan Duomo

If I remember correctly we spent about 45 min in the Duomo then up to the roof and probably about an hour there
When you descend from the roof you are back in the Duomo so we spent maybe another 20-30 min.
We did have timed entry to roof and there wasn’t much wait- this was early October

I’d give it 2.5 plus time to get to and from as long as you have entry time booked in advance

https://ticket.duomomilano.it/en/

I’d agree with 2-2.5 hours. I think I was on the roof about 45 minutes but I have a fear of heights and that was about all I could make myself stay up there, lol. I did the roof first with the timed fast lane pass so I could take the elevator as high as it goes ( still more stairs after that). I was probably in the Duomo about an hour to 1.5 hours including the excavation area.

Two hours is probably good if the crowds are small and you pre-buy tickets. The day we went, in the second week of May last year, there was a music event in front of the cathedral and we weren't allowed in that way. We weren't able to pick up our audio tours and had to take the elevator straight to the roof. That took a while because the line was long and the elevator isn't that big. This was a Friday and our first day of the trip. We were pretty jetlagged and I had had COVID two weeks before which amplified the jet lag. It's all a little fuzzy. I remember it was really hot on the roof and there were a lot of school groups. I think we went to a cafe someplace in the cathedral and had something refreshing. The cathedral itself was enormous and it was hard to find some place to sit and reflect. The Galleria nearby was also fun to visit. It was the one time when I wished McDonald's had put a lot more ice in my Coke. We did a spin on the bull's balls. Hazy but I think this is typical recollection of the first day of a trip. ; )