Day Trip to Pompeii is a real time commitment — fit it in only if it's a priority.
Allow Full day (10–12 hrs).
An astonishing, walkable ancient city — frescoed houses, a forum, plaster casts of victims — that rewards the effort. But it's a serious commitment from Rome: a fast train to Naples then a local line, easily 10–12 hours round trip, and Pompeii itself is vast, hot, and largely unshaded.