Link: Isochronous Application V0.8 [Cartoo]
Cartoo is a web based application that will return an estimate for the distance you could cover from a given starting point in a given time and using a given mode of transport.
http://gyazo.com/a2fa01f74f6f017b8bade9bb79f1d6d7.png
The results returned are intended as estimates only and an allowance should be made for some degree of error.
