Grid references, scale and distance revision notes

Edexcel International GCSE Geography (4GE1), chapter 11: Geographical skills, specification point G5, G1. Free lesson.

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Grid references locate squares and points, while a map scale lets you convert map measurements into real distances. You can also describe the direction between places and give global positions using latitude and longitude.

How to read four- and six-figure grid references

A map grid uses eastings for the upright lines and northings for the lines running across the map. Read eastings first, then northings: go along the map, then up. A four-figure reference names a whole square from its bottom left corner. A six-figure reference gives a more precise point by adding tenths across and tenths up. Square 4323 means easting 43, then northing 23. For a six-figure reference, add the tenths across after the easting, then the tenths up after the northing. The church is 6 tenths across and 4 tenths up in square 4323, so its reference is 436 234.

How to give a compass direction

Describe the direction from the first place named to the second. The farm at 456 249 is north east of the church at 436 234. If you start at the farm and go to the church, the direction is south west.

What a map scale tells you

A scale shows how much smaller the map is than the real land. With a ratio scale, 1 cm on the map represents the number of centimetres shown by the second number on the ground. A scale line can show the same information in kilometres. A grid square is 1 km across on both maps described here, so counting squares gives a quick estimate. At 1:50,000, 1 cm on the map represents 50,000 cm, or 0.5 km, on the ground. So 1 km on the ground is 2 cm on the map. At 1:25,000, 1 cm represents 25,000 cm, or 0.25 km. So 1 km on the ground is 4 cm on the map. A 1:25,000 map shows a smaller area on the…

How to measure straight and winding distances

For a straight distance, measure between the places with a ruler. Multiply the map distance by the scale to find the ground distance, then convert centimetres into kilometres. For a winding feature such as a footpath or river, follow its bends with string or a paper strip, straighten it, and measure it with a ruler. There are 100 cm in a metre and 1,000 m in a kilometre. For a winding route, turn the paper strip at each bend before straightening it.

How to give global positions

Latitude describes how far north or south a place is from the Equator. Longitude describes how far east or west it is from the Prime Meridian. Both are measured in degrees. Write latitude before longitude, and include the direction letter with each number. For example, write 30°N, 20°E.