In many cultures, including much of the English-speaking world, asking someone how much they have saved up can be considered quite personal and potentially disrespectful. Financial matters are often seen as private, and such questions might be perceived as intrusive.
However, the acceptability of this question can vary depending on the context and the relationship between the individuals. Among close friends or family members, it might be more acceptable, especially if the context is appropriate, such as discussing financial planning or sharing personal milestones.
Ultimately, it's important to consider cultural norms and the comfort level of the person you're asking. If in doubt, it might be better to avoid asking directly about specific amounts of savings.