You may think that only schoolchildren and carpenters need a ruler. However, almost everyone needs this tool from time to time. If you don't have a real line, why not use a computer line?
These rulers can be handy if you don't have other tools at hand. But there is no guarantee that the measurement results will be fairly accurate. Therefore, we do not recommend using them for high-precision work. Although services and applications try to automatically calibrate so that the drawn centimeters correspond to real ones, they do not always succeed..
Better to double check them for accuracy. This is easy to do with a standard sized item. For example, using a banknote. So, the length of a 100 or 500 ruble bill is 150 mm, and a 2000 ruble note is 157 mm.
iRuler
iRuler is an online service that has been operating since 2007. Having entered the site, you will see a regular ruler right on your computer screen. Measurements can be carried out both in millimeters and centimeters, and in inches..
The site automatically determines the size of the monitor diagonal and the resolution in order to correctly display the ruler. If the function worked incorrectly, click on the "select your monitor dimension" to specify the diagonal and resolution manually.
This is where you can finish your acquaintance with this simple tool, the service has no other functions..
PiliApp Actual Ruler
PiliApp Actual Ruler is another screen ruler that differs from iRuler in more functionality.
When you first visit the page, the service will ask you to confirm the correctness of the automatic determination of the screen diagonal. If the dimensions do not fit your monitor, you can choose the diagonal from the list or enter the size manually. But there is also an option “I don’t know the size of the monitor”.
In the latter case, you can use the same banknote, credit card, or, for example, an iPhone, if you know its dimensions, to measure the diagonal. If you click on the "drag it" button, the ruler will open in a separate browser window, which can be easily moved to any desired place on the screen.
FreeOnlineRuler
In FreeOnlineRuler there are additional options that are not in the above-mentioned sites. By clicking the mouse, the ruler can be easily dragged to any place on the screen. And if you hold down the Ctrl key while clicking, you can still rotate it. This is useful for measuring objects with irregular geometric shapes.
At the bottom of the page, you can uncheck the display in centimeters or inches if you want only one scale to be shown. And if you tick the "flipped" checkbox, the zero mark will move to the right, and measurements will be made, respectively, from right to left.
The FreeOnlineRuler service also has a calibration tool. Click "Please calibrate your ruler" at the bottom of the screen. Here you can calibrate using a credit card, banknote or sheet of paper with known dimensions.
Ruler by Xalpha Lab
The sites described above are fine for use on a computer, but not on a smartphone. If you want a ruler for your phone or tablet, you need a dedicated app.
If you have an Android smartphone, we recommend using the Ruler app . It was highly rated by users on Google Play (almost 9 thousand users rated it 4.6 points). Drag the height and width guides to match the size and location of the object being measured.
If you click on any free space on the screen, the top menu will open. Here you can switch to the dark theme, change units, calibrate with a coin or credit card, and more.
Of course, since the display of the phone is much smaller than the dimensions of the monitor, it is convenient to measure only small objects with a smartphone app. But in some cases this may be enough.
Google Measure
To work with large objects, we advise you to pay attention to Google Measure . This is an augmented reality app introduced in 2016 that uses a smartphone camera to take measurements. You can save photos of your measurements for future reference. This is a very convenient feature, especially for those who, for example, choose a sofa in a furniture store.
The app works pretty well when used correctly. When testing, he was able to correctly measure a table 182 cm wide, but the protrusion on the table, which is 28 cm, he measured as 25 cm. The application itself warns that his measurements may have an error of these same 3 cm. It is recommended to use it on textured, well illuminated surfaces.
Ruler by Tue Nguyen Minh
If you have an iPhone, you will find just as many applications as for Android. One of the best is 3-in-1 Ruler from Vietnamese developer Tue Nguyen Minh. This application has not only the usual on-screen ruler, but also augmented reality functionality and the ability to print the ruler.
When you launch the app, it will ask for access to the phone's camera. This is necessary for measurements using augmented reality. With a regular ruler, you can measure objects up to 10 centimeters in size.
By the way, the latest versions of the iPhone already have a built-in application called Measurement. It can also use augmented reality.
