EXHIBIT 12(a) UNITED RENTALS, INC. STATEMENT OF COMPUTATION OF SUPPLEMENTAL PRO FORMA RATIO OF EARNINGS TO FIXED CHARGES SUPPLEMENTAL PRO FORMA SUPPLEMENTAL PRO FORMA YEAR ENDED SIX MONTHS ENDED DECEMBER 31, 1997 (1) JUNE 30, 1998 (1) ------------------------ ----------------------- Earnings: Income before provision for income taxes................ $ 86,488,321 $55,493,012 Interest expense...... 74,339,568 32,982,314 Amortization of debt issuance cost........ 1,868,761 934,381 Interest portion of rent expense(2)...... 11,924,284 6,435,188 ------------ ----------- Earnings as adjusted........... $174,620,934 $95,844,895 ============ =========== Fixed charges: Interest expense...... $ 74,339,568 $32,982,314 Amortization of debt issuance cost........ 1,868,761 934,381 Interest portion of rent expense(2)...... 11,924,284 6,435,188 ------------ ----------- Fixed charges....... $ 88,132,613 $40,351,883 ============ =========== Ratio of earnings to fixed charges.......... 2.0x 2.4x - -------- (1) The supplemental pro forma ratio of earnings to fixed charges gives effect to (i) each acquisition completed by the Company after the beginning of the period and the financing thereof, and (ii) completion of the Merger with U.S. Rentals using the "pooling of interest" method of accounting. (2) The interest portion of rent expense is estimated to be one-third of rent expense.