Manhattan Address Algorithm

The Manhattan address algorithm is a rule of thumb for estimating which east-west cross street is nearest to a given building number on one of Manhattan's north-south avenues. It works by dividing the building number by a divisor, usually 20, and adding or subtracting a fixed offset known as the avenue's own tricky number. The method works because Manhattan's grid was built with roughly twenty address numbers between consecutive cross streets, reflecting the borough's standard lot widths and street spacing of about two hundred feet. The algorithm gives only an approximate cross street, not an exact address, but it is widely used for quick navigation.