| What it is | Map distance : ground distance |
| Example | 1:24,000 (USGS standard) |
| Smaller ratio number | More detail, less area |
| Use | Measure distances, plan time |
Map scale is the ratio between a distance on the map and the corresponding distance on the ground, written as a ratio such as 1:24,000. A smaller second number means a larger-scale, more detailed map covering less area; scale lets you measure real distances and plan travel time.
Using it
Convert measured distance on a topographic map into ground distance, then estimate travel by pace count or dead reckoning.
Frequently asked questions
What is map scale?
Map scale is the ratio of distance on the map to actual distance on the ground. A scale of 1:24,000 means one inch on the map equals 24,000 inches (2,000 feet) on the ground. It lets you convert measured map distances into real-world distances.
What's the difference between large-scale and small-scale maps?
A large-scale map (like 1:24,000) shows a small area in great detail, ideal for hiking; a small-scale map (like 1:250,000) shows a large area with less detail, better for overview planning. Counterintuitively, the 'larger' scale has the smaller second number.
How do you measure distance using map scale?
Measure the distance on the map (with the printed scale bar, a ruler, or map string), then convert using the scale ratio. The scale bar is easiest: lay your measurement against it to read the ground distance directly, accounting for trail bends by measuring in segments.
Sources
- Map scale — USGS
- Navigation basics — The Mountaineers