"There is one bicycle for everyone of Amsterdam's 837,000 citizens." That figure comes from the 2017 publication, Cycling Matters, published by the City of Amsterdam. It's safe to say that number was a guesstimate, as are all the statistics you'll find on this subject. Currently, the city's marketing department still touts a number first published in 2015: 881.000 bikes. That number was arrived at using the so-called ‘Wisdom of the Crowd’ methodology. See this footnote to our article, Amsterdam, City of Bikes. That same year, Statistics Netherlands said the 442.693 households (850.000 residents) in Amsterdam together owned 847.000 bicycles — 1.91 bicycle per household. 78% of people 12 years and older owns at least one bike. Currently there are no more recent statistics. We suggest you keep using the 881.000 number. Bonus fact: each year between 12,000 and 15,000 bikes are fished up from the city’s canals