Cover - USD ($)	12 Months Ended
	Apr. 30, 2025	Jun. 23, 2025	Oct. 31, 2024
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Apr. 30, 2025
Current Fiscal Year End Date	--04-30
Document Transition Report	false
Entity File Number	0-1678
Entity Registrant Name	BUTLER NATIONAL CORP
Entity Incorporation, State or Country Code	KS
Entity Tax Identification Number	41-0834293
Entity Address, Address Line One	One Aero Plaza
Entity Address, City or Town	New Century
Entity Address, State or Province	KS
Entity Address, Postal Zip Code	66031
City Area Code	913
Local Phone Number	780-9595
Title of 12(g) Security	Common Stock $.01 Par Value
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
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Document Financial Statement Error Correction [Flag]	false
Entity Public Float			$ 87,863,225
Entity Common Stock, Shares Outstanding		67,232,151
Documents Incorporated by Reference	Portions of the definitive proxy statement to be filed within 120 days of April 30, 2025, pursuant to Regulation 14A under the Securities Exchange Act of 1934 for the Annual Meeting of Shareholders to be held on October 1, 2025, have been incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0000015847
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Fiscal Year Focus	2025