Cover Page - USD ($) $ in Billions	12 Months Ended
	Jan. 31, 2022	Mar. 09, 2022	Jul. 31, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Jan. 31, 2022
Current Fiscal Year End Date	--01-31
Document Transition Report	false
Entity File Number	001-37901
Entity Registrant Name	COUPA SOFTWARE INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-4429448
Entity Address, Address Line One	1855 S. Grant Street
Entity Address, City or Town	San Mateo,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94402
City Area Code	650
Local Phone Number	931-3200
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	COUP
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 16.0
Entity Common Stock, Shares Outstanding		75,066,000
Documents Incorporated by Reference	Portions of the Registrant’s Proxy Statement relating to the 2022 Annual Meeting of Stockholders, scheduled to be filed with the Securities and Exchange Commission within 120 days after the end of the Registrant’s fiscal year ended January 31, 2022, are incorporated by reference into Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0001385867
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY