Understanding Map Grid References

• A grid reference is a system used to assign a location to items on a map.
• This includes settlements, man-made structures, crops, and physical features.
• Grid references can be either four-figure or six-figure numbers.
• The term "GRID" refers to the pattern of squares formed by evenly-spaced vertical and horizontal lines on a map.
• Vertical lines on a map are called Eastings, which are numbered in an eastward direction (left to right).
• Horizontal lines are called Northings, and they increase in a northward direction (bottom to top).
• Eastings are always written before Northings when providing a grid reference.
• Items on the same horizontal line share the same northing number.

Four-Figure Grid Reference

• A four-figure grid reference is a numerical reference that identifies the square in which a place, feature, or point is located.
• Essentially, it serves as the name of the square.
• Each square is defined by two eastings (vertical lines) and two northings (horizontal lines).
• Each grid is has two sets of numbers, being 2 eastings and 2 northings.
• When giving a grid reference, eastings are given first, followed by northings
• Each grid is bordered by two eastings and two northings.
• When using a 4-figure grid, use the lower of the 2 easting/northing numbers.
• The four-figure grid reference for grid square one is easting 22 and northing 36, written as 2236.

Six-Figure Grid Reference

• To create a six-figure grid reference, each grid square is divided into 10 equally spaced vertical and horizontal lines (although these may not be drawn on the map).
• This allows for a more precise location to be identified.
• To give a 6-figure grid reference, identify the eastings and a third number.
• To find the third number add how many tenths the point or place is from the eastings after the first two digits of the four-figure grid reference.
• Example: Point A is 5 tenths away from eastings 41. Add this number to eastings 41 to become 415.
• Identify the northings and a third number.
• The third northings number can be found by counting how many tenths the point/place is from the northings
• Add this number after the second two digits of the four-figure grid reference.
• Example: Point A is 5 tenths away from northings 53. Add this number to northings 53 and it becomes 5355.
• The six-figure grid reference is written by combining the numbers together, such as 415535.