Day trip/Salerno to Sorrento

I question the importance of "visiting Sorrento." It's a perfectly nice place, and a high-priority destination for sun-seekers in the UK, for one example. But it's a post-war, purpose-built, cliff-top (no real beaches), relatively modern construction. Now, Capri, Pompeii, Herculaneum, Naples, Positano, Ravello, Amalfi, are places worth visiting. I would certainly visit Paestum and Pompeii before Sorrento, becaus Salerno has good connections for both.

There is only one "budget" route, that's two SITA (municipal) busses, Salerno-Amalfi, and Amalfi-Sorrento. 2-3 hours, I'd guess (have not done it), depending on traffic on the ONLY two-lane road along the AC. May-September, many standees on this route, or at least the Sorrento end. Second choice, ferry. This ferry may shut down by the end of October, not sure. Download some schedules.

Ferry if running- although that's a long ride!

Train- you'd have to take the train to Pompeii (town) then a taxi to the Pompeii Scavi station to catch the Circumvesuviana (local train)- diff train line) to Sorrento.

We really liked Sorrento (and we liked Salerno!) but like Tim- I'm not sure it's worth the long transit for a day trip.

Private driver is a another option $$$

We stayed in Sorrento for 2 weeks and loved it as a home base to get everywhere else, but it's entirely missable as a daytrip unless there is something specific you're wanting to see. As from the comments above, it will be a slow trip and no matter the method, several hours of your day will be spent getting there and back. I'd probably choose the ferry because at least the views will be enjoyable. There is a Travelmar ferry that should get you to Amalfi and then a few options to get to Sorrento. I don't believe the ferries run after dark so timing is important.

Yeah, it's not worth the time and trouble. There's nothing extraordinary about the town. Spend the time in the well-preserved historic center of Salerno. Or take the train or bus to Paestum for the temple ruins - the best outside of Sicily.