Advanced Placement Calculus examinations were administered to nearly 7,000 students from more than 400 high schools in order to determine the impact of calculator use. Both the Calculus AB and Calculus BC experimental examinations had two sections. Section I items were designed so that a calculator was not needed to arrive at the correct solution. Approximately half of the students were permitted to use calculators on this section. Section II items were developed to require a calculator to arrive at the correct solution. All students were permitted calculator use for these items. Analyses indicated that calculator use resulted in a substantial improvement in performance for 3 of the 40 Section I items. Those with calculators capable of graphics or the taking of derivatives performed better on both sections of the exams than those with scientific calculators. The internal consistency reliability of the Section I items was higher for students not permitted calculator use. A pattern of negative D-DIF values for the Section II items indicated that these items were differentially more difficult for females than the Section I items. The D-DIF value of only one Section I item appeared to be substantially impacted by calculator use. Total test scores were found to be higher for those permitted to use calculators, for males in comparison to females, and for those reporting the use of advanced calculators in comparison to those reporting the use of scientific calculators.