MyOSGB PHP Class is a simple lightweight PHP class written for PHP5. Its purpose is to simplify distance calculations between Eastings and Northings, National Grid References or a combination of all three. It can convert Eastings and Northings to National Grid References and vice-versa. All distance calculations are performed in miles, but there is an optional switch to change this to kilometers. It works exclusively on six digit (100 metre refrencing). Less than 6 will be padded with zeros, in order to force backwards compatibility between the different levels of refrencing. Grid refrences are genearted based on these different levels, but you can override this, if you wish to provide longer or shorter, albeit less accurate points of refrence, with or without spaces. This class is designed to work with the Ordnance Survey's National Grid referencing system only.