20 MISC. PUBLICATION 22 5, U. S. DEPT. OF AGRICULTURE 



Table 31. — Ratios for customary map scales 



Scale l to— 



1,200..- 

 2,500 _ — 



4,800. ... 

 5,280.-.. 

 10,000--. 

 15,840--. 

 20,000--. 

 24,000--. 

 25,000--. 

 31,680... 

 45,000--. 

 63,360-.. 

 90,000--. 

 96,000-.. 

 125,000-. 

 500,000-. 

 1,000,000 

 2,500,000 



Inches per 

 mile 



105.6 

 52.8 

 25. 344 

 13.2 

 12 



6.336 

 4 



3.168 

 2.64 

 2.534 

 2 



1.408 

 1 

 .704 

 .66 

 .507 

 .127 

 .063 

 .025 



Miles per 

 inch 



0.0095 

 .0189 

 .0395 

 .0758 

 .0833 

 .1578 

 .25 

 .3157 

 .3788 

 .3946 

 .5 



.7102 

 1 



1. 4205 

 1. 5152 

 1.9729 

 7. 8914 

 15.7828 

 39. 4571 



Feet per 

 inch 



50 

 100 

 208 

 400 



440 



833 



1,320 



1,667 



2,000 



2.083 



2,640 



3.750 



5.280 



7.500 



8,000 



10, 417 



41.667 



83, 333 



208. 333 



Meters per 

 inch 



15.2 



30.5 



63.5 



121.9 



134.1 



254.0 



402.3 



508.0 



609.6 



635.0 



804.7 



1,143.0 



1,609.3 



2.286.0 



2, 438. 4 



3,175.0 



12,700.0 



25, 400. 1 



63, 500. 1 



Feet per 

 Hs inch 



2 

 4 



8.3 

 16 



17.6 

 33.3 

 52.8 

 66.7 

 80 



83.3 



105.6 



150 



211.2 



300 



320 



416.7 



1,666.7 



3,333.3 



8,333.3 



Acres per 

 square inch 



0.06 

 .23 

 1.00 

 3.67 

 4.44 

 15.94 

 40.00 

 63.77 

 •91.83 

 99.64 

 160 

 323 

 640 

 1,291 

 1,469 

 2,491 



Square miles 



per square 



inch 



0.0001 

 .0004 

 .0016 

 .0057 

 .0069 

 .0249 

 .0625 

 .0996 

 .1435 

 . 1557 

 .2500 

 .5044 

 1.00 

 2.02 

 2.30 

 3.89 

 62.3 

 249 

 1,557 



Table 32.— 



Vertical aerial photo scale relations 





Representative fraction 



Inches per 

 mile i 



Representative fraction 



Inches per 

 mile i 



1:31,680 



2 



2.64 



2.696 



2.755 



2.816 



2.88 



2.947 



3 



3.017 



3.091 



3.168 



3.249 



3.335 



3.425 



3.52 



3.621 



3. 727 



3.84 



3.96 



4 



1:15,500 - 



4.088 



4.224 



4.370 



4.526 



4.693 



4.874 



5 



5.069 



5.28 



5.510 



5.76 



6 



6.034 



6.336 



6.669 



7 



7.04 



7.454 



7.92 



8 



1:24,000 



1:15,000 



1:23,500 



1:14,500 



1:23,000 



1:14,000 



1:13,500 



1:22,500— 



1:22,000 



1:13,000 - 



1:21,500—. 



1:12,672 



1:21,120 



1:12,500 



1:21,000 



1:12,000 



1:20,500 -. . 



1:11,500 



1:20,000 



1:11,000 



1:19,500. . . 



1:10,560 



1:19,000 



1:10,590- . 



1:18,500.. . 



1:10,000 



1:18,000 



1:9,500 



1:17,500 



1:9,051 . . - 



1-17,000 



19,000 



1:16,500 



1:8,500 - 



1:16,000 



1:8,000 



1:15,840 



1:7,920 - . 







i Scale in inches per mile = representative fracrionX63,360 (constant), 

 reverse. 



Figures in bold face computed in 



