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.