The walkscore.com website will calculate a walkability score, and can even provide your commute times via various methods (car, bike, walking, transit). The commute aspect even provides the elevation changes along the route.
The calculation takes into account proximity to restaurants, banks, schools, mass transit, parks, businesses, etc. to produce a numeric score from 0 ("Car Dependent") to 100 ("Walker's Paradise").
The site asks "What makes a neighborhood walkable?", and describes it thusly:
- A center: Walkable neighborhoods have a center, whether it's a main street or a public space.
- People: Enough people for businesses to flourish and for public transit to run frequently.
- Mixed income, mixed use: Affordable housing located near businesses.
- Parks and public space: Plenty of public places to gather and play.
- Pedestrian design: Buildings are close to the street, parking lots are relegated to the back.
- Schools and workplaces: Close enough that most residents can walk from their homes.
- Complete streets: Streets designed for bicyclists, pedestrians, and transit.
Anyway, it's a cool web-site, go take a look at it.