Adjust the ruler with your screen size :

Size of your screen in inches :

How to find the size in inches of your screen ?

You can try to find the size in inches of your screen by typing the references of it on the internet. There is also another way, if you know the size in cm of the diagonal, then you just need to divide it by 2.54 to get the dimension in inches.

Adjust the ruler with a real object :

Example :

In this example, calibrate it by placing your map on it and adjust until the black line overlaps the map using the arrows to decrease or increase the size of it.

Online ruler - Measure actual size in cm and mm

How to use an online ruler in cm

To use a online ruler, you just need to setup your screen size in inch by following the instructions. If this is not possible, there is another method by using everyday objects and setting it to them. Once done, we invite you to validate your changes, a message will appear to inform you that the measurements are well calibrated.

The evolution of the rule over time

The ruler in geometry is a tool used to draw straight lines and measure distances. It is composed of a flat surface with a graduated border. Rulers are usually made of metal, plastic or wood. It was invented by the Egyptians around 4,500 years ago. At the time, rulers were made of wood or bone, and were graduated in inches and lines. The Egyptians used them to draw straight lines in the sand and to measure distances. Over the centuries it has been improved and perfected. In 1854, the English Stanley Rule and Level Company marketed the first metal measuring tool.

Why use an online ruler?

A ruler is a very precise measuring tool that can measure the length, width or height of an object. Without it, it would be very difficult to know what the exact size of an object is. It is found in France generally graduated in centimeters and millimeters. Today the most famous object allowing the calculation of short distance is the "meter".