That's right. It's simple to remember once you get the hang of it. 100% grade: every foot forward is one foot of climb, or every meter forward is one meter of r

That's right. It's simple to remember once you get the hang of it. 100% grade: every foot forward is one foot of climb, or every meter forward is one meter of rise. 10% grade: ten feet forward, one foot up, or ten meters forward, one meter up. 110% grade: one foot forward, 1.1 feet up, or one meter forward, 1.1 meters up. 6% grades are steep enough to earn warning signs, if you pay attention to signage in the mountains. Sonora Pass, for example, has sections of 26% grade. That sounds immensely steep (and is, for driving), but it sounds more reasonable when you say "every 50 feet forward, you've climbed 13 feet." Solve the triangle, and that's 14.574°. If you've been over the Sonora Pass, you know that it feels like you're in a rocket climbing vertically at a couple points, and you might be surprised to learn that's only 14.6° of grade. 22nd Street in SF is over 31%, IIRC, and is one of the steepest streets I can think of.