Map.getScale

 // The default map in the Code Editor is a built-in ui.Map object called "Map". 
 // Let's refer to it as "defaultMap" for clarity. 
 var 
  
 defaultMap 
  
 = 
  
 Map 
 ; 
 // ui.Map objects can be constructed. Here, a new map is declared. 
 var 
  
 newMap 
  
 = 
  
 ui 
 . 
 Map 
 ({ 
  
 center 
 : 
  
 { 
 lat 
 : 
  
 0 
 , 
  
 lon 
 : 
  
 0 
 , 
  
 zoom 
 : 
  
 1 
 }, 
  
 style 
 : 
  
 { 
 position 
 : 
  
 'bottom-right' 
 , 
  
 width 
 : 
  
 '400px' 
 } 
 }); 
 // Add the newMap to the defaultMap. 
 defaultMap 
 . 
 add 
 ( 
 newMap 
 ); 
 // You can set the viewport of a ui.Map to be centered on an object. 
 // Here, the defaultMap is centered on a point with a selected zoom level. 
 var 
  
 geom 
  
 = 
  
 ee 
 . 
 Geometry 
 . 
 Point 
 ( 
 - 
 122.0841 
 , 
  
 37.4223 
 ); 
 defaultMap 
 . 
 centerObject 
 ( 
 geom 
 , 
  
 18 
 ); 
 defaultMap 
 . 
 addLayer 
 ( 
 geom 
 , 
  
 { 
 color 
 : 
  
 'orange' 
 }, 
  
 'Googleplex' 
 ); 
 // Map extent can be fetched using the ui.Map.getBounds method. 
 print 
 ( 
 'defaultMap bounds as a list' 
 , 
  
 defaultMap 
 . 
 getBounds 
 ()); 
 print 
 ( 
 'defaultMap bounds as a dictionary' 
 , 
  
 ee 
 . 
 Dictionary 
 . 
 fromLists 
 ([ 
 'w' 
 , 
  
 's' 
 , 
  
 'e' 
 , 
  
 'n' 
 ], 
  
 defaultMap 
 . 
 getBounds 
 ())); 
 print 
 ( 
 'defaultMap bounds as GeoJSON' 
 , 
  
 defaultMap 
 . 
 getBounds 
 ({ 
 asGeoJSON 
 : 
  
 true 
 })); 
 // Map center point can be fetched using the ui.Map.getCenter method. 
 print 
 ( 
 'defaultMap center as a Point geometry' 
 , 
  
 defaultMap 
 . 
 getCenter 
 ()); 
 // Map zoom level can be fetched using the ui.Map.getZoom method. 
 print 
 ( 
 'defaultMap zoom level' 
 , 
  
 defaultMap 
 . 
 getZoom 
 ()); 
 // Map scale can be fetched using the ui.Map.getScale method. 
 print 
 ( 
 'defaultMap approximate pixel scale' 
 , 
  
 defaultMap 
 . 
 getScale 
 ());