Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 28, 2019	Jun. 29, 2019
Document And Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 28, 2019
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, par value $0.001
Trading Symbol	MASI
Security Exchange Name	NASDAQ
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
Market Value of non affiliate stock at end of Q2		$ 6.8
Entity Common Stock, Shares Outstanding	53,793,530
Documents Incorporated by Reference	Items 10, 11, 12, 13 and 14 of Part III of this Annual Report on Form 10-K incorporate information by reference from the registrant’s proxy statement for the registrant’s 2020 Annual Meeting of Stockholders to be filed with the Securities and Exchange Commission within 120 days after the close of the fiscal year covered by this annual report on Form 10-K.
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0000937556
Current Fiscal Year End Date	--12-28