This brief introductory text presents the basic principles of calculus from the engineering viewpoint. Excellent either as a refresher or as an introductory course, it focuses on developing familiarity with the basic principles rather than presenting detailed proofs. Topics include differential calculus, in terms of differentiation and elementary differential equations; integral calculus, in simple and multiple integration forms; time calculus; equations of motion and their solution; complex variables; complex algebra; complex functions; complex and operational calculus; and simple and inverse transformations. Advanced subjects comprise integrations and differentiation techniques, in addition to a more sophisticated variety of differential equations than those previously discussed. It is assumed that the reader possesses an acquaintance with algebra and trigonometry as well as some familiarity with graphs. Additional background material is presented as needed.