To convert address to lat long type the address with city name, street name to get more accurate lat long values. This free online tool is a gps coordinates converter which convert a text string containing an address in a couple of coordinates of latitude and longitude. This code is based on Minibots class.
Geocode conversion from address to latitude and longitude coordinates
To convert an address to its GPS coordinates I use an external services. These functionality is available on many services and also Google Maps has its own methods to geocode an address. This free online tool doesn't use Google geocoding service, even if I use Google Maps to show address.
The geocoding is made using my Minibots class which is available on Codecanyon for few dollars. The Minibots class performs many kind of calls to performs nice tricks for coders and the geocoding is made with two different free services Goecode.xyz and Locationiq.com. They both are free but they both need a registration to receive an API key.
If you want to find the distance between two points, use my calculate distance on Google maps tool.