scale | Python Fiddle

# Author: jamie.vleeshouwer@csiro.au

def getScale(areaBounds_ha):
    
	# Note areaBounds_ha is the size of the polygon's bounds, not to size of the polygon itself.
    area_m2 = areaBounds_ha * 10000

maxSize_MB = 1024 								    			# Maximum file size
    resolutions = [1,2,5,10,15,30,50,100,250,500,1000,5000,10000]	# Common resolutions ranging from 1m to 10km
    pixelSize_b = 32							    				# Size of a floating point number
    
    pixelsAvailable = maxSize_MB * 1024 * 1024 / pixelSize_b		# The number of pixels that can be packed into the file size for the given datatype

# Find the first resolution that fits within the file size constraint
    bestScaleToFit = [resolution for resolution in resolutions if area_m2 / (resolution * resolution) <= pixelsAvailable][0]
    
    return bestScaleToFit

# Testing

#fieldBoundSize_ha = 150 # Cotton field
#fieldBoundSize_ha = 850
#fieldBoundSize_ha = 3500
#fieldBoundSize_ha = 90000000 # NSW
#fieldBoundSize_ha = 1500000000 # Australia
fieldBoundSize_ha = 52000000000 # Earth

scale = getScale(fieldBoundSize_ha)
print(scale)

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