Simplifying query by adding Computed Column, performance impact?
Moving the calculation to the view won't change performance - it's still done at runtime. So all you've changed is the complexity of the outer query.

In order to change performance you would need to add the computed column to the table, and persist it or index it. This means the work of the calculation is done at insert/update time instead of query time. (Persisting only works in 2005+.)

Now, other factors are at play too. For example, do you have any evidence that this calculation actually affects performance? Maybe the query performs the same without it? Also using the view may cause other performance issues, for example if it involves additional columns, calculations or tables that this query doesn't actually need.