Macau covers roughly 33 square kilometres. You can cross the whole territory by bus in well under an hour, and that single fact creates the most common mistake visitors make here: because it is small, it gets treated as a day trip from Hong Kong. Ferry over mid-morning, Senado Square and the Ruins of St Paul's before lunch, an hour wandering a resort, back on an evening sailing.
That day is not wasted. It is simply the thinnest possible reading of a place that has three genuinely different characters stacked on top of each other: a dense Sino-Portuguese old town, a village-scale island, and a strip of reclaimed land carrying enormous integrated resorts. Seeing one of them is a sample. Seeing all three is the trip.
The honest answer on length is this. Two nights is the working minimum, three nights is the number I would give it, and a fourth only earns its place if you want beach time or you are travelling slowly on purpose. Below two nights you are choosing between the old town and the resorts rather than seeing both. At three you get the peninsula on foot, Taipa and Cotai for an evening, and Coloane at the pace Coloane deserves.
Understand the three pieces before you book a hotel
Macau is a peninsula attached to mainland China at its northern edge, plus two former islands to the south, Taipa and Coloane, which are now joined together by Cotai, a wedge of reclaimed land built specifically to hold resorts.
The peninsula holds the old town: the UNESCO-listed Historic Centre, the squares, the churches, the temples and the fortresses, along with the tightest and most atmospheric streets in the territory. It is a walking district and should be treated as one.
Taipa keeps a small village core of pastel shophouses and a strip of restaurants, and it is where the airport and one of the two ferry terminals sit.
Cotai is the resort corridor between Taipa and Coloane, home to the Venetian, the Londoner, the Parisian, Studio City, City of Dreams and their neighbours. It is indoors, air-conditioned and effectively weatherproof, which matters more for planning than it first sounds.
Coloane, at the far southern end, is the one that surprises people: a quiet village by the water, a mustard-yellow chapel, hillside paths and two dark-sand beaches, with almost none of the scale of the rest.
Where you sleep decides how much of your time you spend in transit. A peninsula hotel puts you inside the walking day and makes evenings in the old town easy. A Cotai resort gives you the pools and the shows on your doorstep and turns every old-town morning into a twenty-minute ride. Both are defensible choices. Choosing without noticing the difference is what produces a trip that feels like commuting.