At the Titanic's beam, or widest point at the nautical waterline, it measured 92 feet 6 inches. Compared to modern ocean cruisers, this is somewhat small; the Costa Concordia, which foundered in 2012, measured 116 feet at the beam.
The Titanic wasn't much wider than other contemporary ships because the limitation on ship width isn't how large you can build them, but rather how wide the dock accommodation is. Most of the Titanic's size was in its length, a full 882 feet 9 inches. The Titanic's Olympic-class design was a larger version of owner White Star Line's earlier ship, the Adriatic, with radical modifications to withstand the heavier stress of a larger hull.