A National Grid Reference represents a specific geographical location on a map. It is widely used in the United Kingdom. The most commonly used National Grid Reference contains both letters and numbers, such as NN 150 160, where each set of three digits represents a 100-meter coordinate and the letter represents a specific grid square. Government agencies frequently use National Grid References when describing survey data and displaying maps. Ireland uses a similar National Grid Reference system.
Open the Free Map Tool webpage (see Resources). This site features an interactive map of Britain. Click on your location. The output displays your National Grid Reference.
Visit the Free Map Tool Convert Postcode to NGR page (see Resources). Enter your mailing postcode in the query box to get the corresponding National Grid Reference.
Go to the Ordnance Survey website (see Resources). This site links to a document that gives step-by-step instructions for finding your National Grid Reference on your own.