To convert an ngr in this example we will use tq30047995 to easting and northing first using the table below look for letters at the start of your ngr. Great britain is covered by grid squares measuring 100 kilometres across and each grid square is identified by two letters as shown in diagram a.
Identify letter for 100 000 metre grid square in which the point is located.
Os map reference letters. That way you can give what is known as a 6 figure grid reference. The grid reference is always for the bottom left hand corner of the grid square you are in. The centre point of square tq therefore has a grid reference of tq 50 50.
4 figure map references when giving a 4 figure grid reference you should always give. Each os grid square has two letters which correspond to two numbers. Ordnance survey os is the national mapping agency for great britain.
These are linked to the national grid which provides a unique reference system and can be applied to all os maps of great britain at all scales. An abbreviated number where the two national grid letters are omitted usually used if the context of the grid reference is obvious 609 543 or 609543 on os landranger map 115. Or provided ordnance survey have not recently re jigged their site click here.
6 figure for example 192454 identifies a 100 metre square within a single kilometre square on an os map. Wgs84 co ordinates example lat 53 870659 long 1 200235 or lat 53 870659n long 1 200235w. The ordnance survey os devised the national grid reference system and it is heavily used in their survey data and in maps based on those surveys whether published by the ordnance survey or.
People may also use this style to quote a reference for a place that is local to you. The ordnance survey national grid reference system is a system of geographic grid references used in great britain distinct from latitude and longitude it is often called british national grid bng. The bottom left of each lettered square starts at 0 and goes to 100 in each direction.
Wgs84 co ordinates example lat 53 870659 long 1 200235 or lat 53 870659n long 1 200235w. The agency s name indicates its original military purpose see ordnance and surveying which was to map scotland in the wake of the jacobite rising of 1745 there was also a more general and nationwide need in light of the potential threat of invasion during the napoleonic wars since 1 april 2015 ordnance survey has. Square on an os map.
Discovery series map grid. If you need to convert an os grid reference then click here. Let s give a grid reference for lugnaquillia with the following steps.
Tip if you are working from a map then the numbers that correspond to the map location are printed as smaller prefix figures at each of the four corners of the explorer and landranger o s maps.