White dwarfs are the evolutionary end product of stars with low and intermediate masses. The evolution of white dwarfs can be understood as a cooling process, which is relatively well known at the moment;. For this reason, wide binaries containing white dwarfs are a powerful tool to constrain stellar ages. We have studied several wide binaries containing white dwarf.,,, with two different purposes: when the age of the companion of the white dwarf can be determined with accuracy, we use the binary to improve the knowledge about the white dwarf member. On the contrary, if the companion is a low-mass star with no age indicator available, the white dwarf member itself is used to calibrate the age of the system. In this contribution we present some results rising both methodologies to constrain the ages of wide binaries.