From Google:
Since water expands as it freezes, the mass of ice is slightly less per unit volume than water. Incidentally, for water that is already near the freezing temperature (0°C at standard atmospheric pressure), freezing increases volume by almost 1%. Density of water: ... Solid Ice: 0.9167 g/cm³
When ice melts, the volume of water is smaller than the volume of the ice. How does the mass of the water compare to the mass of the ice?
2 answers
Everything PsyDAG has reported from Google is correct but you should know that most of what that article is about is density;i.e., mass/unit volume. Your question is about the mass of ice vs mass water. That is the same. That is, ice to water gives smaller volume BUT the mass is the same. If you have 5 g water and you freeze it you will have 5 g ice.