Map scale calculator
A map scale such as 1:24,000 means one unit on the map is 24,000 units on the ground. Enter a scale to see it as inches to feet or miles and centimeters to meters, then convert distances between the map and the ground.
Last updated: · Free tool by InsightSpatial
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Common map scales
| Scale | 1 inch = | 1 cm = | Used for |
|---|---|---|---|
| 1:48 | 4 ft | 0.48 m | Architectural plans: 1/4 inch = 1 foot |
| 1:240 | 20 ft | 2.4 m | Engineering site plans: 1 inch = 20 feet |
| 1:600 | 50 ft | 6 m | Engineering site plans: 1 inch = 50 feet |
| 1:1,200 | 100 ft | 12 m | Plats and site plans: 1 inch = 100 feet |
| 1:24,000 | 2,000 ft | 240 m | USGS 7.5-minute topographic maps: 1 inch = 2,000 feet |
| 1:63,360 | 1 mi | 633.6 m | One inch to the mile (older USGS maps of Alaska) |
| 1:100,000 | 1.58 mi | 1 km | USGS 30 × 60-minute maps: 1 cm = 1 km |
| 1:250,000 | 3.95 mi | 2.5 km | USGS 1° × 2° maps: 1 inch ≈ 3.95 miles |
Web map zoom levels
Web maps such as Google Maps and OpenStreetMap have no single scale. At the equator, on a typical screen, each zoom level halves the ground distance per pixel. Away from the equator, multiply by the cosine of the latitude: at 40° north, distances per pixel are about 23% smaller.
| Zoom | Meters per pixel | Approximate scale |
|---|---|---|
| 5 | 4,892 | 1:18,489,335 |
| 10 | 152.9 | 1:577,792 |
| 12 | 38.2 | 1:144,448 |
| 14 | 9.555 | 1:36,112 |
| 15 | 4.777 | 1:18,056 |
| 16 | 2.389 | 1:9,028 |
| 17 | 1.194 | 1:4,514 |
| 18 | 0.597 | 1:2,257 |
| 19 | 0.299 | 1:1,128 |
| 20 | 0.149 | 1:564 |
Equator, 256-pixel tiles, 96 dots per inch. Screens and print settings change the exact scale.
Questions
What does a scale of 1:24,000 mean?
One unit on the map equals 24,000 of the same units on the ground. One inch on the map is 24,000 inches, or 2,000 feet; one centimeter is 240 meters.
What is the difference between a large-scale and a small-scale map?
A large-scale map, such as 1:1,200, shows a small area in great detail. A small-scale map, such as 1:1,000,000, shows a large area with less detail. The larger the number after the colon, the smaller the scale.
How do I measure distance on a paper map?
Measure between the two points with a ruler, multiply by the number after the colon, and convert the units. On a 1:24,000 map, 3.5 inches is 84,000 inches, which is 7,000 feet or about 1.33 miles.
Does a web map have a fixed scale?
No. The scale changes with zoom level, with latitude (Web Mercator stretches the map away from the equator), and with your screen. Use the scale bar on the map, or the zoom table on this page as a guide.