The present invention relates to a multifunctional ruler. A user can use the ruler to easily measure a length and mark the measured value by easily converting the measurement unit. According to the present invention, a display unit is formed on a side of the ruler to measure a length and a measurement unit conversion display unit is formed on a through marking hole formed on the inner side unit of a keyboard body to have columns spaced apart by a predetermined gap. Accordingly, the ruler can easily convert and display a measurement in a 100-fold unit such as a 1000-fold unit or size for a length of a capacity.
