Originally Posted by joejack951

Do you know what cadence (rotations of the crank per minute) that you normally ride at? If so, enter that into the calculator and figure out what gearing you'll need to be able to maintain that cadence at 5-6mph. That should allow you to comfortably climb those hills.

For example, I just inputted a 30 small chainring with a 26 large cog, 700 x 23 tires, and 90 rpm. At that cadence, 8.1mph is the slowest you can go with your current gearing. Any slower and your cadence must fall. With a 30-32 low gear, you'll be able to ride at 6.6mph and 90 rpms (getting closer to what you want, based on my assumptions of course). A 26-32 low gear will get you down to 5.7mph at 90 rpms.