There's no central, universally agreed-upon registry of all Waldorf schools worldwide. The Association of Waldorf Schools of North America (AWSNA) and the worldwide umbrella organization, the International Waldorf Federation (IWF), don't maintain comprehensive lists of every school globally. Many schools are independently operated and may not be formally affiliated with any larger organization.
Therefore, it's impossible to give a precise number of international Waldorf schools. Any number you find will be an estimate and likely an underestimate.