Had a look on bikely, which gives you aa few options ranging from
http://www.bikely.com/maps/bike-path/Toronto-Guelph-Bernie 101.2Km
http://www.bikely.com/maps/bike-path/Toronto-Guelph-2
104.7Km
http://www.bikely.com/maps/bike-path/Guelph-Toronto-1
92.3Km
http://www.bikely.com/maps/bike-path/Guelph-Toronto-2-lakeshore
107.2Km
http://www.bikely.com/maps/bike-path/Guelph-Toronto-3-Miss-Road
97.8Km
http://www.bikely.com/maps/bike-path/Option-6-Toronto-to-Guelph-Rich
100Km
http://www.bikely.com/maps/bike-path/Option-7-Toronto-Guelph-Denise-Glen-Williams
103.2Km
Take your pick. If you click on the "show" button, it can tell you the approx evelavation gain/loss of each ride.