Exhibit 99.1
Return on Invested Capital ("ROIC") and Economic Return Calculations GAAP to non-GAAP reconciliation (dollars in thousands):
			Fiscal year ended
			October 2,			October 3,			September 28,
			2021			2020			2019
Operating income, as reported			$	176,268		$	153,372		$	142,055
Restructuring and other charges			3,267			6,003			1,678
Adjusted operating income			179,535			159,375			143,733
Tax rate			13.0		%	14.0		%	16.0		%
Adjusted operating income (tax effected)			$	156,195		$	137,062		$	120,736
Average invested capital			$	1,014,742		$	979,981		$	923,107
ROIC			15.4		%	14.0		%	13.1		%
WACC			8.1		%	8.8		%	9.0		%
Economic Return			7.3		%	5.2		%	4.1		%
Average Invested Capital	Fiscal 2021
	October 2,		July 3,			April 3,			January 2,			October 3,		Average invested capital
	2021		2021			2021			2021			2020
Equity	$	1,028,232	$	1,020,450		$	1,013,952		$	1,006,959		$	977,480
Plus:
Debt and finance lease obligations - current	66,313		60,468			50,229			148,408			146,829
Operating lease obligations - current (1) (2)	9,877		9,130			9,314			9,351			7,724
Debt and finance lease obligations - long-term	187,033		187,690			188,730			188,148			187,975
Operating lease obligations - long-term (2)	37,970		33,193			34,751			37,052			36,779
Less:
Cash and cash equivalents	(270,172)		(303,255)			(294,370)			(356,724)			(385,807)
	$	1,059,253	$	1,007,676		$	1,002,606		$	1,033,194		$	970,980	$	1,014,742
Average Invested Capital	Fiscal 2020
	October 3,		July 4,			April 4,			January 4,			September 28,		Average invested capital
	2020		2020			2020			2020			2019
Equity	$	977,480	$	944,821		$	892,558		$	908,372		$	865,576
Plus:
Debt and finance lease obligations - current	146,829		145,993			107,880			67,847			100,702
Operating lease obligations - current (1) (2)	7,724		8,061			8,546			9,102			—
Debt and finance lease obligations - long-term	187,975		188,626			186,327			186,827			187,278
Operating lease obligations - long-term (2)	36,779		38,077			39,617			41,764			—
Less:
Cash and cash equivalents	(385,807)		(296,545)			(225,830)			(252,914)			(223,761)
	$	970,980	$	1,029,033		$	1,009,098		$	960,998		$	929,795	$	979,981

Average Invested Capital	Fiscal 2019
	September 28,		June 29,		March 30,		December 29,		September 19,		Average invested capital
	2019		2019		2019		2018		2018
Equity	$	865,576	$	860,791	$	875,444	$	905,163	$	921,143
Plus:
Debt and finance lease obligations - current	100,702		138,976		93,197		8,633		5,532
Operating lease obligations - current (1) (2)	—		—		—		—		—
Debt and finance lease obligations - long-term	187,278		187,581		187,120		187,567		183,085
Operating lease obligations - long-term (2)	—		—		—		—		—
Less:
Cash and cash equivalents	(223,761)		(198,395)		(184,028)		(188,799)		(297,269)
	$	929,795	$	988,953	$	971,733	$	912,564	$	812,491	$	923,107

(1)	Included in other accrued liabilities on the Consolidated Balance Sheets.
(2)	In fiscal 2021, Plexus adopted and applied Topic 842 to all leases using the modified retrospective method of adoption. The prior year comparative information has not been restated and continues to be reported under the accounting standards in effect for fiscal 2019.