CONSOLIDATED STATEMENT OF INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 30, 2023	Dec. 31, 2022	Jan. 01, 2022
Income Statement [Abstract]
Net sales	$ 13,122	$ 12,653	$ 11,747
Cost of goods sold	8,839	8,842	7,929
Selling, general and administrative expense	2,778	2,600	2,435
Operating profit	1,505	1,211	1,383
Interest expense	303	201	205
Other income (expense), net	(162)	(108)	274
Income from continuing operations before income taxes	1,040	902	1,452
Income taxes	258	180	353
Earnings (loss) from unconsolidated entities	6	9	3
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest, Total	788	731	1,103
Net income (loss) attributable to noncontrolling interests	13	2	7
Income from discontinued operations, net of taxes	176	231	392
Net income attributable to Kellanova	$ 951	$ 960	$ 1,488
Earnings from continuing operations, per basic share	$ 2.27	$ 2.14	$ 3.21
Earnings from discontinued operations, per basic share	0.51	0.67	1.15
Net Earnings Per Common Share - Basic	2.78	2.81	4.36
Earnings from continuing operations, per diluted share	2.25	2.12	3.19
Earnings from discontinued operations, per diluted share	0.51	0.67	1.14
Net Earnings Per Common Share - Diluted	$ 2.76	$ 2.79	$ 4.33