A calculator watch is a digital watch with a built-in calculator, usually including buttons on the watch face. Calculator watches were first introduced in the 1970s and continue to be produced, despite falling from their peak popularity during the 1980s. The most dominant brands were the Casio Databank series and Timex.

Most calculator watches perform only basic arithmetic operations (addition, subtraction, multiplication, and division). However, there are several models with additional functions: scientific, including transcendent and trigonometry, in models Casio CFX-20, CFX-200, CFX-400 and Citizen 49–9421, financial functions (Casio CBA-10) and also TV remote control functions (CMD-40B and CMD-30B).

Usually, calculator watches operate with eight-digit numbers; however, calculator watches can work with six digits (for example, Casio C-801) or ten-digit (Casio CBA-10).