Document and Entity Information	9 Months Ended
	Oct. 02, 2021 shares
Document And Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Oct. 02, 2021
Document Transition Report	false
Entity File Number	001-33642
Entity Registrant Name	MASIMO CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0368882
Entity Address, Address Line One	52 Discovery
Entity Address, City or Town	Irvine,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92618
City Area Code	(949)
Local Phone Number	297-7000
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	MASI
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller Reporting Company	false
Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	55,221,689
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000937556
Current Fiscal Year End Date	--01-01