EXHIBIT 11.0 NORTHWEST PIPE COMPANY COMPUTATION OF EARNINGS PER SHARE (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS) THREE MONTHS ENDED NINE MONTHS ENDED SEPTEMBER 30, SEPTEMBER 30, -------------------- ------------------- 1997 1996 1997 1996 ------ ------ ------ ------ Net income as reported $3,299 $2,677 $8,676 $8,046 ------ ------ ------ ------ ------ ------ ------ ------ Earnings per share $ 0.50 $ 0.48 $ 1.31 $ 1.45 ------ ------ ------ ------ ------ ------ ------ ------ Weighted average shares outstanding: Common stock 6,406 5,294 6,404 5,281 Common stock issuable upon exercise of stock options 239 245 213 256 ------ ------ ------ ------ Shares used in per share calculations 6,645 5,539 6,617 5,537 ------ ------ ------ ------ ------ ------ ------ ------