How many smartphones are sold worldwide each year?

How to get close to this number

Divide the installed base by the replacement cycle. This site's companion question puts phones in use at around seven billion, and people replace them roughly every three to four years. Seven billion divided by a four-year cycle gives annual shipments in the low billions.

The trend is the part that inverts expectation: shipments peaked in 2016 and have drifted down since. The market did not shrink — the installed base kept growing — but replacement cycles stretched as phones stopped improving fast enough to justify upgrading. A falling sales figure with a growing user base means the product got good enough.

The concentration is the other structural fact: two manufacturers take about a third of units between them, with the rest spread across many. Note that these are shipments to retail rather than sales to users, which is the standard industry measure and slightly leads actual demand.