Reading maps like a geographer
Maps are full of tools that help you understand them. Once you know how to use the legend, scale, compass rose and coordinates, you can read almost any map.
The legend
The legend, or key, explains the symbols and colours on a map.
| Symbol | Meaning |
|---|---|
| ★ | capital city |
| ● | city or town |
| — (thick line) | highway |
| – – – (dashed line) | border |
| blue | water |
| green | parks or forests |
Different maps use different symbols, so always check the legend first.
The compass rose
A compass rose shows directions.
- The cardinal directions are north (N), south (S), east (E) and west (W).
- The intermediate directions are halfway between them: northeast (NE), southeast (SE), southwest (SW) and northwest (NW).
Example: Vancouver is northwest of Toronto. Halifax is east of Montréal.
On most maps, north is at the top. If there’s no compass rose, assume north is up, but check!
Scale
A map is much smaller than the real place. The scale shows how map distances compare to real distances.
Types of scale
- Bar scale: a line marked with distances, such as 0 — 50 — 100 km.
- Written scale: 1 cm = 10 km
- Ratio scale: 1:100 000, meaning 1 unit on the map equals 100,000 of the same units in real life
Using a bar scale
- Measure the distance between two places on the map with a ruler or a strip of paper.
- Line it up with the scale bar.
- Read the real distance.
Example: If 1 cm = 10 km, and two towns are 4.5 cm apart on the map, they are about 45 km apart.
Large scale and small scale
- A large-scale map shows a small area in lots of detail, like a city park.
- A small-scale map shows a large area with less detail, like the whole world.
Grids
Many maps use a grid: lines that divide the map into squares. Letters run along one side and numbers along the other.
To find a place, look up its grid square in the map index, such as C4. Find column C and row 4. Where they meet is the square you need. This is how street maps and atlases help you find places quickly.
Latitude and longitude
Geographers use an imaginary grid around the whole Earth.
Latitude
- Lines of latitude run east–west, like rungs on a ladder.
- They measure distance north or south of the equator (0°).
- They go up to 90°N (North Pole) and 90°S (South Pole).
Longitude
- Lines of longitude (meridians) run from the North Pole to the South Pole.
- They measure distance east or west of the prime meridian (0°), which runs through Greenwich, England.
- They go up to 180°E and 180°W.
Coordinates
Together, latitude and longitude give exact coordinates for any place. Latitude is written first.
| Place | Approximate coordinates |
|---|---|
| Ottawa | 45°N, 76°W |
| Washington, D.C. | 39°N, 77°W |
| Vancouver | 49°N, 123°W |
| Equator in Ecuador | 0°, 78°W |
Memory trick: Latitude lines are flat. Longitude lines are long, from pole to pole.
Putting it all together
To plan a trip using a map:
- Check the legend to understand symbols.
- Use the compass rose to find directions.
- Use the scale to measure distances.
- Use the grid or coordinates to find exact places.
Try it yourself
- Draw a map of your school with a legend, a compass rose, a scale and a grid.
- On a map of your province or state, measure the distance between two cities using the scale.
- Find your city’s latitude and longitude.
- Give a friend coordinates on a world map and see if they can find the place.
Quick recap
- The legend explains map symbols.
- The compass rose shows cardinal and intermediate directions.
- The scale shows how map distances compare to real distances.
- Grids help you find places using letters and numbers.
- Latitude and longitude give exact coordinates anywhere on Earth.