计时马表，或称马表（英语：chronograph），是一种有计时功能的手表，是将秒表的功能结合于手表之中。计时码表于 1720年由英国人 George Graham乔治·格林汉 发明。

无论是机械手表，石英手表，甚至LCD显示数字表，都有计时码表的产品。LCD数字手表的价钱是三者中最低，但计时功能却是最为精确，精度可达百分之一秒或千分之一秒。石英的计时码表价钱较贵，精度多数为十分之一秒 。而机械计时码表的精度是最差，只能以秒计算，但由于机芯结构复杂，因此价钱最为昂贵。

A chronograph is a specific type of watch that is used as a stopwatch combined with a display watch. A basic chronograph has an independent sweep second hand; it can be started, stopped, and returned to zero by successive pressure on the stem. Less simple chronographs use additional complications and can have multiple independent hands to measure seconds, minutes, hours and even tenths of a second. In addition, many modern chronographs use moveable bezels as tachymeters for rapid calculations of speed or distance. Louis Moinet invented the chronograph in 1816 for use in tracking astronomical objects. Chronographs were also used heavily in artillery fire in the mid to late 1800s. More modern uses of chronographs involve piloting airplanes, car racing, diving and submarine maneuvering.