EXHIBIT 12(a) UNITED RENTALS (NORTH AMERICA), INC. STATEMENT OF COMPUTATION OF SUPPLEMENTAL PRO FORMA RATIO OF EARNINGS TO FIXED CHARGES Supplemental Pro Forma --------------------------------- Year Nine Months Ended Ended December 31, September 30, ------------ ------------- 1997 1998 ---- ---- (dollars in thousands) Earnings: Income before provision for income taxes and extraordinary items................ $ 89,234 $ 63,216 Interest expense...... 80,021 60,344 Amortization of debt issuance cost........ 124 684 Interest portion of rent expense(2)...... 12,078 13,784 -------- -------- Earnings as adjusted........... $181,457 $138,028 ======== ======== Fixed charges: Interest expense...... $ 80,021 $ 60,344 Amortization of debt issuance cost........ 124 684 Interest portion of rent expense(2)...... 12,078 13,784 -------- -------- Fixed charges....... $ 92,223 $ 74,812 ======== ======== Ratio of earnings to fixed charges.......... 2.0x 1.8x - -------- (1) The supplemental pro forma ratio of earnings to fixed charges gives effect to each acquisition completed by the Company after the beginning of the period and the financing thereof as if all such transactions had occurred at the beginning of the period. (2) The interest portion of rent expense is estimated to be one-third of rent expense.