<Page> Exhibit 12.1 RATIO OF EARNINGS TO FIXED CHARGES (DOLLARS IN THOUSANDS) <Table> <Caption> DigitalNet Government Solutions, LLC ------------------------------------------------------------------------------ Period from January 1, 2002 Six months Year ended December 31, through ended ---------------------------------------------- November 25, June 30, 1998 1999 2000 2001 2002 2002 ------- ------- ------- ------- --------------- ---------- Income before income taxes $10,911 $25,994 $ 6,475 $32,822 $ 43,058 $23,858 Plus: Interest on indebtedness -- -- -- -- -- -- Portion of operating lease rental expense estimated to be representative of interest 582 689 582 946 1,271 695 ------- ------- ------- ------- -------- ------- Earnings(1) $11,493 $26,683 $ 7,057 $33,768 $ 44,329 $24,553 ======= ======= ======= ======= ======== ======= Fixed charges: Interest on indebtedness $ -- $ -- $ -- $ -- $ -- $ -- Portion of operating lease rental expense estimated to be representative of interest 582 689 582 946 1,271 695 ------- ------- ------- ------- -------- ------- Total fixed charges(1) $ 582 $ 689 $ 582 $ 946 $ 1,271 $ 695 ======= ======= ======= ======= ======== ======= Ratio of earnings to fixed charges 19.75x 38.73x 12.13x 35.70x 34.88x 35.33x ======= ======= ======= ======= ======== ======= <Caption> DigitalNet Holdings, Inc. ------------------------------------------------------------------------------------------------- Period from September 7, 2001 Pro forma Pro forma (inception) as adjusted Three months Six months as adjusted for Six months through Year ended Year ended ended ended the six months ended December 31, December 31, December 31, June 30, June 30, ended June 30, June 30, 2001 2002(2) 2002(3) 2003 2002 2002(3) 2003 ------------ ----------- ------------ ------------ ----------- ---------- ---------- Income before income taxes $ (698) $ (1,740) $ 22,429 $ 1,866 $ (1,216) $ 12,184 $ 2,729 Plus: Interest on indebtedness -- 1,517 12,583 4,037 -- 6,291 8,141 Portion of operating lease rental expense estimated to be representative of interest 12 41 1,312 285 18 713 583 -------- -------- -------- -------- -------- -------- -------- Earnings(1) $ (686) $ (182) $ 36,324 $ 6,188 $ (1,198) $ 19,188 $ 11,453 ======== ======== ======== ======== ======== ======== ======== Fixed charges: Interest on indebtedness $ -- $ 1,517 $ 12,583 $ 4,037 $ -- $ 6,291 $ 8,141 Portion of operating lease rental expense estimated to be representative of interest 12 41 1,312 285 18 713 583 -------- -------- -------- -------- -------- -------- -------- Total fixed charges(1) $ 12 $ 1,558 $ 13,895 $ 4,322 $ 18 $ 7,004 $ 8,724 ======== ======== ======== ======== ======== ======== ======== Ratio of earnings to fixed charges -- x(4) -- x(4) 2.61x 1.43x -- x(4) 2.74x 1.31x ======== ======== ======== ======== ======== ======== ======== </Table> - ------------- (1) For purposes of determining the ratio of earnings to fixed charges, earnings are defined as income before taxes plus fixed charges. Fixed charges consist of interest expense, including amortization of deferred financing fees and debt discounts, and a portion of operating lease rental expense estimated to be representative of interest. (2) On November 26, 2002, we acquired all of the membership interests of Getronics Government Solutions, L.L.C. (now DigitalNet Government Solutions, LLC or DGS). Our results of operations for the year ended December 31, 2002 include the operating results of DGS from November 26, 2002 through December 31, 2002 along with that of DigitalNet Holdings, Inc. for the entire year ending December 31, 2002 (3) The pro forma as adjusted statement of operations data gives effect to (i) the DGS acquisition and the related transactions, (ii) the sale of the old notes, (iii) the 2003 Credit Facility, and (iv) the exchange offer as if each of the transactions had occurred on January 1, 2002. (4) Earnings of DigitalNet Holdings, Inc. for the period from September 7, 2001 (inception) through December 31, 2001, the year ended December 31, 2002, and the six months ended June 30, 2002 were not sufficient to cover fixed charges. The deficiency was approximately $698,000 for the period from September 7, 2001 (inception) through December 31, 2001, approximately $1.7 million for the year ended December 31, 2002, and approximately $1.2 million for the six months ended June 30, 2002.