Much research was invested in the last decade to develop differencing methods to identify the changes performed between two model versions. Typically, these changes are captured in an explicit difference model. However, quantifying the distance between model versions received less attention. While different versions of a model may have the same amount of changes, their distance to the base model may be drastically different. Therefore, we present distance metrics for models. We provide a method to generate tool support for computing domainspecific distance measures automatically. We show the benefits of distance measures over model differences in the use case of searching for the explanation of model evolution in terms of domain-specific change operations. The results of our experiments show that using distance metrics outperforms the usage of common difference models.