This presents many of the most common options among users.

You can also select the size from the drop-down list (which opens when you click the button ▾, which is adjacent to the numeric input field). Then click the ↹ Calibrate or press the button ↵ Enter on the keyboard. Enter this value in the input field located in the lower left corner of the ruler image. Specify the size of the diagonal of your screen in inches ('). You can calibrate it in one of the following two ways: 💁 How to use this online rulerįor the ruler to display correctly (i.e., in proportion to the actual physical size), it must be calibrated.

The maximum length of the ruler (fully visible when displayed on a sufficient screen) is 20 inches, or 50 centimeters (500 millimeters) for the metric scale option. This online app works on both computers with a large screen (laptops, PCs, monoblocks or smart TVs) and mobile gadgets (phones, phablets, tablets, e-ink readers). You can make the necessary measurements on any device that allows you to browse the web. If you want to measure the actual size of a small object in inches or centimeters and you don’t have a real ruler at hand, this virtual on-screen online ruler will help you.