Exhibit 99.1

PLEXUS CORP.

NON-GAAP SUUPLEMENTAL INFORMATION

(in thousands, except per share data)

(unaudited)

ROIC Calculation

	Six Months Ended				Three Months Ended				Six Months Ended
	March 30, 2013				December 29, 2012				March 31, 2012
Operating income	$	44,672			$	21,484			$	49,530
	x		2		x		4		x		2
Annualized operating income	89,344				85,936				99,060
Tax rate	8			%	6			%	10			%
Tax impact	-		7,148		-		5,156		-		9,906
Operating income (tax effected)	$	82,196			$	80,780			$	89,154
Average invested capital	$	645,402			$	640,992			$	619,311
ROIC	12.7			%	12.6			%	14.4			%

	March 30, 2013			December 29, 2012			September 29, 2012
Equity	$	669,047		$	664,515		$	649,022
Plus:
Debt—current	2,893			10,310			10,211
Debt—non-current	258,789			259,516			260,211
Less:
Cash and cash equivalents	(276,507		)	(274,183		)	(297,619		)
	$	654,222		$	660,158		$	621,825

Fiscal 2013 second quarter average invested capital (March 30, 2013, December 29, 2012 and September 29, 2012) was $645,402.

Fiscal 2013 first quarter average invested capital (December 29, 2012 and September 29, 2012) was $640,992.

	March 31, 2012			December 31, 2011			October 1, 2011
Equity	$	615,296		$	581,811		$	558,882
Plus:
Debt—current	17,518			17,446			17,350
Debt—non-current	261,542			265,941			270,292
Less:
Cash and cash equivalents	(257,754		)	(248,284		)	(242,107		)
	$	636,602		$	616,914		$	604,417

Fiscal 2012 second quarter average invested capital (March 31, 2012, December 31, 2011 and October 1, 2011) was $619,311.