A conservative estimate places the worldwide homeless population at 100 million (approximately 1.5%).  However, this does not include people who live in semi-permanent structures (e.g., tents, shanties, vehicles, abandoned buildings) or live from shelter to shelter.  Approximately 1% of the US population will experience homelessness in any given year.  

 

United Nations Commission on Human Rights

National Coalition for the Homeless – Fact Sheet