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Flying Ruler Pro

Move to measure.

Measure just about anything with your iDevice with Flying Ruler

Flying Ruler Pro

Flying Ruler Pro
Flying Ruler Pro
$1.99 in the App Store

Measure just about anything with your iDevice with Flying Ruler.

What is it about?

The Flying Ruler app allows you to measure in the most original way: by just moving your device from one point to another.

For those who...

  • It’s great for projects around your home.

Not for those who...

  • Accuracy varies by iDevice. Older iDevices like iPhone 4 will have an error rate that’s much higher. Also, if you have a case around your iDevice, you’ll have to measure it to help improve accuracy.

Why we love it

If you don’t have a ruler or protractor readily available, download Flying Ruler today. It works like magic.

App Screenshots

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App Details

Utilities Education
Last updated
May 20, 2022
Release date
August 4, 2013
More info

App Store Description

The Flying Ruler app allows you to measure in the most original way: by just moving your device from one point to another.

Measurements take place extremely quickly and at the same time they are quite accurate. We are constantly improving our computational algorithm for more than 9 years!


Editor's Choice — 148Apps

*** Only on iOS ***

To try this technology for free you can install the app "Goniometer Plus". This free app measures the angle as you move the device.


"I was impressed with Flying Ruler’s accuracy. It works quickly and effectively", "It’s the perfect addition to anyone’s app collection" — 148apps 4.5 / 5 (MUST HAVE)

"This thing is awesome" —

"I literally said “wow!” when I first used this app and I think it’s a truly impressive marvel of mobile technology", "The Flying Ruler Rules" — AppPicker (Cons: there is nothing negative to say about this app)

*** Measure distance with good precision, no matter the lighting or conditions ***

Flying Ruler is a tape measure, ruler, protractor and a goniometer (angle-measurer). It is four devices in one app, providing you with the quickest way to measure a distance or an angle.

The secret of the program is that it is based on the principles of the inertial navigational system (INS): the position of the device is determined with the help of the accelerometer and the gyroscope.

The app has different modes so you can choose which mode is better and easier to use on each occasion. You can measure with the body of the device in one mode or with a virtual ruler in another. You can not only measure an object but also the distance between two walls. You use the same methods to measure angles as the app allows you to measure angles both on a surface area and between surfaces through space.

You can choose either inches or centimeters. The maximum distance is only limited by the value of the indicator which consists of 999 ft for the imperial system and 99 m for the metric system.

When measuring, you can avoid obstacles and therefore you can measure anything.

Flying Ruler is suitable for measuring not only large, but also very small distances with the accuracy of a standard ruler.

The app also allows you to save a measurement by taking a photograph of the measurement and mark the place that was measured.

Don’t forget to show your friends and colleagues how the app works – believe us, they will be impressed.


We took 100 consecutive measurements and got these results:

On iPhone 13:

• Mean squared error - 0.14%
• Maximum inaccuracy - 0.4%

On iPhone 7:

• Mean squared error - 0.15%
• Maximum inaccuracy - 0.4%

On iPhone 6s:

• Mean squared error - 0.28%
• Maximum inaccuracy - 1.1%

The accuracy of measurements depends on the device, however the error rarely exceeds 1.5%. You can always increase accuracy by making a series of measurements. If you make a series of measurements, the degree of error is usually 0.3% or less.

Angles can be measured with the app to an accuracy of one degree so the app can easily take the place of a protractor or a goniometer (angle measurer).


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