Cover - USD ($)
 12 Months Ended
Sep. 30, 2021
Jan. 20, 2022
Mar. 31, 2021
Document Type 10-K    
Amendment Flag false    
Document Annual Report true    
Document Transition Report false    
Document Period End Date Sep. 30, 2021    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2021    
Current Fiscal Year End Date --09-30    
Entity File Number 001-37464    
Entity Registrant Name CEMTREX, INC.    
Entity Central Index Key 0001435064    
Entity Tax Identification Number 30-0399914    
Entity Incorporation, State or Country Code DE    
Entity Address, Address Line One 276 Greenpoint Ave. Suite 208    
Entity Address, City or Town Brooklyn    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 11222    
City Area Code 631    
Local Phone Number 756-9116    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 18,141,241
Entity Common Stock, Shares Outstanding   23,673,210  
ICFR Auditor Attestation Flag false    
Common Stock [Member]      
Title of 12(b) Security Common Stock    
Security Exchange Name NASDAQ    
Series-1 Preferred Stock [Member]      
Title of 12(b) Security Preferred Stock, Series 1    
Security Exchange Name NASDAQ    
Series 1 Warrants [Member]      
Title of 12(b) Security Series 1    
Security Exchange Name NASDAQ