People disagree about this more than about anything else in Malta, and the disagreement is the answer. Sight-collectors are done in four or five days and say so. Travellers who like history fill a week or two happily and say the island is underrated. Both are right about themselves. Nobody credible says under three.
The one point everyone agrees on: if you have five days or more, Gozo deserves nights, not a day trip. “One day on Gozo was not enough” is the most repeated regret in every forum about Malta.
A long weekend — three nights
One base, on the harbour. Valletta for the atmosphere or Sliema for the logistics. Day one Valletta: the co-cathedral first thing before the cruise wave, the Barrakka gardens, the noon gun, the harbour ferry to the Three Cities in the afternoon. Day two the south: the temples at Ħaġar Qim and Mnajdra on their clifftop, a boat at the Blue Grotto, Marsaxlokk late when the coaches have gone. Day three Mdina and Rabat, arriving after five when the Silent City earns its name. No Gozo, and no regret about it at this length.
A Valletta street at lunchtime, between the cruise waves.
Four to five days
Same base; add a temples-and-harbour day (the Hypogeum if you booked months ago, Tarxien if you didn’t, the Three Cities properly) and a Gozo day trip by the fast ferry with a hire car at Mġarr. This is where sight-collectors finish. It is a good trip. It is not the one most people remember.
Five to seven days
Now split: four nights on the harbour and two or three on Gozo. Gozo’s register is different — slower, greener, villages rather than a city — and it only shows itself when you wake up there. Ġgantija before the day-boats, the salt pans at golden hour, a ftira from a Nadur bakery on a bench, Dwejra’s Inland Sea in calm weather. Do it at the end, not the beginning: arriving on Gozo after Malta feels like exhaling. What to do with those nights is in Gozo.
A week to two
Everything above plus the things that need a whole day each: the west coast and Dingli cliffs, the north-west bays by wind, a dive or a snorkel trip, Comino on the eight o’clock boat, a festa weekend in summer. Two weeks is not too long for someone who likes stone and the sea. It is far too long for someone who wanted a beach holiday.
When changing base helps, and when it doesn’t
The island is fifty minutes across. Moving between Valletta and Sliema is not a change of base; it is a change of hotel. The only move that changes the trip is the Gozo Channel. A north base plus Gozo is the one other sensible split, for a family with a car and a beach-first brief.
Three hotels in seven days is luggage administration. Two bases, one ferry, is the pattern.
Where the time goes
What makes Malta feel bigger than it is: the bus network radiates from Valletta, so a cross-island trip can take three times what the map suggests; the cruise hours fill Valletta and Mdina at midday and the coach hours fill Marsaxlokk mid-morning; and the Hypogeum, if you get a ticket, is a fixed appointment the day bends around. Plan by the hour, not by the kilometre, and the days stretch.
For which base, see Where to stay in Malta. For whether any of this needs a car, Getting around.