Understanding National Grid References

Every point in Ireland can be picked out by a letter and unique number e.g. Enniskerry, Co. Wicklow is O 223  173 – this is the national grid reference.

Locate the square with the correct letter – always a large blue letter in our example “O”.

Now locate the  vertical grid line to the left of the point you wish to find and read the figure labelling the line on the top or bottom margin e.g. “22”. Now estimate tenths from the grid line to the point you wish to find “3”. These are the EASTINGS always read first!

Next locate the  horizontal grid line below the point you wish to find and read the figure labelling the line on the right or left margin e.g. “17”. Now estimate tenths from the grid line to the point you wish to find “3”. These are the NORTHINGS.