RRSP vs. Mortgage Calculator What's smarter: invest in your RRSP or pay down your mortgage? If you have extra money at the end of each month or a lump sum to invest, you've probably wondered whether it is smarter to invest it in your RRSP or pay down your mortgage. The answer to this question will depend on many things, including the terms of your mortgage and what you expect to earn on your RRSP. This calculator can help you understand which strategy may be best for you. Tell us about your mortgage: My current mortgage rate is:   % The principal outstanding is: $   My monthly mortgage payment is (remember to subtract property taxes, if included): $   If you invested the money in your RRSP, the annual rate of return you'd expect to earn on your investments is:   % I have a lump sum payment of: $   I would like to increase my monthly mortgage/RRSP payment by: $   My marginal tax rate is:   %