The X Mark I Pro sits at the top of Canon's calculator lineup, built for professional mathematicians and engineers who need genuine scientific depth rather than a basic four-function tool. A large 61 × 25mm textbook display shows complex expressions and equations exactly as written, with 610 advanced functions covering calculus, matrices, and complex numbers.

Nineteen store-and-recall memories and 79 built-in scientific constants keep repetitive lookups off a separate reference sheet, while 172 metric conversions handle unit switching without a second device. A thin, flat matte silver-and-white body keeps it closer to a piece of stationery than a bulky office tool.