What a convoluted way to calculate this.

In order to retire well your main focus needs to be paying off your mortgage and any loans. Don't even bother calculating this or that if you still have loans and mortgages. Get rid of them ASAP.

Only after being debt free, estimate your retirement income. Focus first on CPP and any supplemental income. Estimate your expenses. You will be surprised to find out that your expenses are relatively small in retirement and in many cases your CPP plus Guaranteed income supplement should cover that. Any saving that you have or have contributed to after paying off your mortgage would be icing on the cake.

You will be surprised that your property taxes will be the highest item on your expenses along with food.  You don't have to live in a very expensive home unless you can. Cook your own meals and eat out no more than once in two weeks. It will improve your health. 

By saving before paying off mortgage first, all you do is make investor advisors rich.