How many active volcanoes are there?
The absolute number of volcanoes that exists depends on your definition: active only, active, dormant plus extinct volcanoes? And even if we decide on a definition, nobody has really counted all of the volcanoes, especially the tens on thousands on the sea floor.
The best guess is 1511 volcanoes have erupted in the last 10,000 years and should be considered active. This number is from the Smithsonian Institution book, “Volcanoes of the World: Second Edition” compiled by Tom Simkin and Lee Siebert.