I’ve done well over an hour before (one way), but it definitely takes planning so not anywhere close to casual. At that point, perhaps other transportation may be used to return. And/or even if a daily/weekly occurrence, it takes discipline to do things like leave on time and stay informed throughout the day to handle weather events, plus wearing certain clothing to handle sweat and sun and rain etc. Biking is definitely preferable to walking for that level of distance/time, though I’ve done both.
More routinely, and perhaps with little notice, maybe… 20 minutes? (one way) It’s hard to say bc it depends on what stores are where, whether the purchases will fit comfortably into my bag, etc. But I’d leave at a moment’s notice for such a trip if need be and the conditions are conducive to it.
What about you: what’s your cutoff?
Yeah, it really depends on a lot of factors, so it’s not like there’s one supreme answer.
Where I live now, which is a rural area, there’s basically nothing within a viable walking distance aside from neighbors. Even then, there are no walkways or sidewalks between houses/properties, so I would be taking my life into my own hands (for those not familiar, that’s an idiom) to walk along the roadway to another house. And yes, we’ve literally had people get hit by vehicles and die out here while walking on/along the roads.
When I lived in suburban and urban areas, my tolerance for walking places was much higher as longer, weather permitting. When I lived off campus during my college years, for example, I didn’t mind walking 45 - 60 minutes to get to campus. And if I was having car trouble, it wasn’t uncommon for me to walk that much or more to get to a grocery store or the mechanic’s shop.
You could park in the furthest parking space as you walk into a store, for nostalgia’s sake:-).