Cover Page Document - USD ($) $ / shares in Units, $ in Billions	12 Months Ended
	Dec. 30, 2023	Jan. 27, 2024	Jun. 30, 2023
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 30, 2023
Document Transition Report	false
Entity File Number	1-4171
Entity Registrant Name	Kellanova
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	38-0710690
Entity Address, Address Line One	412 N. Wells Street
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60654
City Area Code	269
Local Phone Number	961-2000
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
ICFR Auditor Attestation Flag	true
Entity Public Float			$ 19.2
Entity Common Stock, Shares Outstanding		340,678,265
Documents Incorporated by Reference [Text Block]	Parts of the registrant’s Proxy Statement for the Annual Meeting of Shareowners to be held on April 26, 2024 are incorporated by reference into Part III of this Report.
Closing price per share of common stock			$ 67.40
Amendment Flag	false
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Entity Central Index Key	0000055067
Current Fiscal Year End Date	--12-30
Document Financial Statement Error Correction [Flag]	false
Common stock
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $.25 par value per share
Trading Symbol	K
Security Exchange Name	NYSE
1.000% Senior Notes Due 2024
Entity Information [Line Items]
Title of 12(b) Security	1.000% Senior Notes due 2024
Trading Symbol	K 24
Security Exchange Name	NYSE
1.250% Senior Notes Due 2025
Entity Information [Line Items]
Title of 12(b) Security	1.250% Senior Notes due 2025
Trading Symbol	K 25
Security Exchange Name	NYSE
0.500% Senior Notes Due 2029
Entity Information [Line Items]
Title of 12(b) Security	0.500% Senior Notes due 2029
Trading Symbol	K 29
Security Exchange Name	NYSE