Map Scale and Effective Resolution

The traditional paper map is accurate to the width of a line, 0.5 mm.  When paper maps are digitized, their accuracy transfers to the digital data.  Some digital data sets may be created with better source materials, but because of the scale at which they are intended to be displayed, the number of points digitized, the care with which they are selected, and the number of decimal points carried may only be good enough for the intended scale.

Scale Effective Resolution (m) Data Set
1:2500 1.25  
1:10,000 5  
1:24,000 12 7.5' quadrangle
1:50,000 25  
1:100,000 50 Original TIGER data
1:250,000 125 1x2 quadrangle, JOG
1:500,000 250  
1:1,000,000 500  
1:2,000,000 1000 US National Atlas
1:10,000,000 5000  

Approximate conversions, degrees to metric.

Last revision 1/22/2014