1. Pixels per inch (PPI).
  2. Compared to the size of common items.
  3. Referring to your screen size in inches. Below, we have listed some of the best online rulers belonging to these categories. READ MORE: Top 5 Websites To Create Cartoon Avatar Online Free (2021)

#1 iRuler

This is one of the best online rulers available on the internet. You can use this ruler to measure in metric as well as inches. iRuler is calibrated based on the size of your screen.

1 Best Online Rulers for Free Measurements1.1 #1 iRuler1.2 #2 PiliApp Online Ruler1.3 #3 Actual Size Ruler1.4 #4 Free Online Ruler1.5 #5 Ruler.onl1.6 #6 Ginifab Online Ruler1.6.1 Conclusion

If the ruler is not able to recognize the size of your screen, you can manually specify the size of the ruler. Then, you can verify it by measuring any known object using this online ruler. WEBSITE: https://iruler.net/

#2 PiliApp Online Ruler

If you want to eliminate the rigidity and move your ruler freely around your screen, you must use PiliApp Online Ruler. To enable this feature, you can use the ‘drag it’ option. It also provides a comparison tool, which you can use to know the actual size of your screen. WEBSITE: https://www.piliapp.com/actual-size/cm-ruler/

#3 Actual Size Ruler

This ruler uses the pixels per inch (PPI) technology to accurately measure and display a ruler on your screen. You can use it to measure in both metric and inches. The Actual Size Ruler can be placed horizontally as well as vertically on your screen, depending on your requirement. It is one of the most accurate online rulers. WEBSITE: https://www.piliapp.com/actual-size/inch-ruler/

#4 Free Online Ruler

This is another simple online ruler that you can use. However, you need to calibrate it before you start using it to measure objects in metric and inches. You can even drag this ruler on your screen. WEBSITE: https://preciseruler.com/

#5 Ruler.onl

If you are looking for a tool that is compatible with any device and can be used to measure any object then, this is the right tool for you! The users are provided with a detailed guide to help them in using this virtual ruler optimally. However, there are some limitations to this ruler. It has a maximum length of 20 inches or 50 cm. Also, you need to calibrate this ruler before you start using it on your device. WEBSITE: https://ruler.onl/

#6 Ginifab Online Ruler

Using this online ruler is quite simple due to its friendly user interface. It supports both metric and inches. WEBSITE: https://www.ginifab.com/feeds/cm_to_inch/actual_size_ruler.html READ MORE: How To Download JW Player Videos Easily Online on Browser

Conclusion

These are some of the best online rulers which you can find on the internet. Each one of them has a unique set of features. You can check them out and decide which one to use on your device. However, you must know that online rulers are less accurate than physical rulers. If we have missed out on any such useful online ruler which supports both metric and inches, then please let us know about it in the comments section below. This is all you need to know about online free rulers. However, if you have any queries in the steps listed above, then please let us know about it in the comments section below.

Top 6 Best Online Rulers Free  Measure MM CM  INCH  - 96