Barcelona 3 day itinerary help

On my 2016 trip I visited La Sagrada Familia and Parc Guell on separate days so each could be the first stop. I think your plan is fine. However, I think you may not want to take the metro from Parc Guell to Museu Picasso, because it's quite a walk from the park down to the metro station--about a mile. Although the direction is downhill, that's probably farther than you're expecting, especially considering that the park itself requires some walking. Google Maps says you can get bus 92 from the park to a metro station. Alternatively, there were taxis hanging out just outside the entry gate to the park when I visited.

My trip was in early August, so definitely peak period, but Enric has warned that Barcelona doesn't have slow periods, so you should expect to find the Picasso Museum massively crowded.

Thanks acraven! If we start at 10 am at La Sagrada Familia, take the metro to the Diagonal station, walk around to find a place to eat and have a 1 hour lunch, what time do you think would be reasonable for Casa Mila? I'm considering purchasing tickets online too although if ticket buying queues aren't that long around mid-afternoon, I would prefer to buy when we get there so we are not in a rush.

Same question for Park Guell and Museu Picasso as I will definitely have to buy tickets online for both sights and need to have an idea of the time for Museu Picasso. Now I wonder if I should rearrange the itinerary so Museu Picasso, which is always busy, is scheduled for first thing in the morning as well.

I don't dare give you aggregate time estimates because 1) I'm a very fast walker and 2) I had a nice, long stay in Barcelona and didn't pay attention to how much time I spent doing most things.
You can use Google Maps to estimate your walking time between key points. It will also estimate public-transportation times, but I wouldn't necessarily trust those.

For La Sagrada Familia without a tower ascent, I think 90 minutes would be adequate for a large percentage of visitors, and most would probably spend a bit less time. 90 minutes would give you some time in both the museum and the shop. If you're going to take a lot of pictures or buy all your holiday gifts in the shop, you'll need extra time.

Allowing an hour for lunch may be inadequate if you're expecting a sit-down meal rather than a sandwich or a salad in a café-style place. I can only suggest that you pad your schedule a lot. Use the extra time to walk around the Eixample, looking at the exteriors of the many interesting buildings.

At Parc Guell it will matter a great deal whether you want to line up to go inside the gatekeeper's cottage. (I did not.) I think the line was already 45 minutes long by the time I noticed it. The park is quite large. I stayed in the Monumental Zone (the part you pay for), but that's only a part of the park. I think an hour inside the park would be about the rock-bottom minimum; otherwise, why traipse all the way out there? You could certainly spend a great deal more time than that.

I think I spent at least 2 hours in the Picasso Museum. That included no time waiting in line because I took the Tourist Office's Picasso tour. Crowding will almost certainly be a factor. It will slow your progress through the museum because you'll have to wait to get close enough to see some of the paintings. Of course, it might be so crowded that you give up quickly.

Someone suggested using a smartphone (or tablet with Wi-Fi) in the morning to book entry to Barcelona sights for later in the day when ones schedule is a bit clearer. That might work for Casa Mila (I am not guaranteeing it), but I think trying to handle the Picasso Museum that way would be risky. Another possibility is to check the official websites to see whether the places you want to visit have extra-cost wildcard tickets that don't tie you to a specific entry time. (I don't know whether they're day-specific.) I know that some Barcelona sights make such tickets available. That would allow you the flexibility you're seeking without any chance of a sell-out.

I've decided to schedule our must-sees (SF, Museu Picasso, Park Guell) as first stops. That way I can purchase tickets online without worrying about which time to set them for. I've already made a wrong time entry choice booking tickets for the Royal Apartments at the Alcazar in Sevilla as I didn't realize the Cathedral didn't open til 11 am.

Anyway, I've checked the La Pedrera website; they do not require the email confirmation to be printed out and afternoon entry times do not appear to be too busy even for the same day. I think I may be able to purchase the ticket using my mobile phone that morning. I will start to keep an eye on ticket availability a few days before. Thank you for your detailed input acraven!

Ashley, I think it's smart to schedule as many key sights as you can first thing in the morning. I believe it will lead to a less hectic and more flexible visit. You'll have the freedom to detour down an interesting street on a whim. To me, that's a lot of the fun of a city like Barcelona.