Document And Entity Information - USD ($)	12 Months Ended
	May 31, 2021	Aug. 27, 2021	Nov. 30, 2020
Document Information Line Items
Entity Registrant Name	BIOMERICA INC
Document Type	10-K
Current Fiscal Year End Date	--05-31
Entity Common Stock, Shares Outstanding		12,510,210
Entity Public Float			$ 66,938,974
Amendment Flag	false
Entity Central Index Key	0000073290
Entity Current Reporting Status	Yes
Entity Voluntary Filers	Yes
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	May 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Interactive Data Current	Yes