Annual report pursuant to Section 13 and 15(d)


Cover - USD ($)
12 Months Ended
Dec. 31, 2021
Mar. 08, 2022
Mar. 07, 2022
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Annual Report true    
Document Transition Report false    
Document Period End Date Dec. 31, 2021    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2021    
Current Fiscal Year End Date --12-31    
Entity File Number 333-193087    
Entity Registrant Name FOCUS UNIVERSAL INC.    
Entity Central Index Key 0001590418    
Entity Tax Identification Number 46-3355876    
Entity Incorporation, State or Country Code NV    
Entity Address, Address Line One 2311 East Locus Court    
Entity Address, City or Town Ontario    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 91761    
City Area Code (626)    
Local Phone Number 272-3883    
Title of 12(b) Security Common Stock, $0.001 par value    
Trading Symbol FCUV    
Security Exchange Name NASDAQ    
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     $ 112,565,464
Entity Common Stock, Shares Outstanding   43,259,741  
Auditor Name BF Borgers CPA PC    
Auditor Location Lakewood, CO    
Auditor Firm ID 5041