Net Loss Per Share Attributable to Guardant Health, Inc. Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table sets forth the computation of the basic and diluted net loss per share attributable to Guardant Health, Inc. common stockholders:

	Year Ended December 31,
	2019			2018			2017
	(in thousands, except per share data)
Net loss	$	(67,851	)	$	(84,263	)	$	(83,221	)
Adjustment of redeemable noncontrolling interest	(7,800		)	(800		)	—
Net loss attributable to Guardant Health, Inc.	(75,651		)	(85,063		)	(83,221		)
Deemed dividend related to repurchase of Series A convertible preferred stock	—			—			(4,716		)
Deemed dividend related to change in conversion rate of Series D convertible preferred stock	—			—			(1,058		)
Net loss attributable to Guardant Health, Inc. common stockholders, basic and diluted	$	(75,651	)	$	(85,063	)	$	(88,995	)
Net loss per share attributable to Guardant Health, Inc. common stockholders, basic and diluted	$	(0.84	)	$	(2.80	)	$	(7.07	)
Weighted-average shares used in computing net loss per share attributable to Guardant Health, Inc. common stockholders, basic and diluted	90,597			30,403			12,582

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share attributable to Guardant Health, Inc. common stockholders for the periods presented as they had an anti-dilutive effect:

	Year Ended December 31,
	2019	2018	2017
	(in thousands)
Convertible preferred stock (on an as if converted basis)	—	43,898	44,818
Stock options issued and outstanding	5,976	7,527	5,179
ESPP obligation	52	22	—
Preferred stock warrants (on an as if converted basis)	—	6	8
Common stock warrants	—	208	382
Restricted stock units	252	—	—
Common stock subject to repurchase	31	46	28
Total	6,311	51,707	50,415