At previous blogs such as about a sign on a road or running along Tokaido, I mentioned a sign "XXkm from Nihombashi." Here is the real one.
南に4kmはこのあたりじゃけど、他の方面ならどれくらい？ 何かいいのないかしら… と思って探していたら、世の中には便利なものがありますね。
I was wondering that 4km to south is around here, but how about other directions? Where would be? Then I did bit searching for an useful site and found this.
だいたいの目安にするにはいいのでは。
I think it'd work fine as a rough measurement.
英語サイトならこんなのもありました。
Here is one of English sites.
Free Map Tools: Radius Around Point
このFree Map Tools、面白い。違うページでは「時速XXkmで歩いて／ジョギングで／走って…YY時間でどこまで行けるか？」も示してくれます。
This website is interesting. On the other page, you can get information about "How far you could go, if you walk by XXkph/jogging/running... in YY hours."
ちなみにこれは東京から時速4kmで24時間歩いてどこまで行けるか、の図。
For instance, this is a map of walking at 4kph in 24 hours' area from Tokyo.