Cover Page - shares	3 Months Ended
	Mar. 30, 2024	Apr. 27, 2024
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Entity Registrant Name	Kellanova
Document Period End Date	Mar. 30, 2024
Document Transition Report	false
Entity File Number	1-4171
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 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
Entity Common Stock, Shares Outstanding (in shares)		341,883,645
Amendment Flag	false
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2024
Entity Central Index Key	0000055067
Current Fiscal Year End Date	--12-28
Common Stock, $.25 par value per share [Member]
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 [Member]
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 [Member]
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