A simple, user-friendly and accurate ruler for your phone!

Use a coin or a credit card to calibrate the ruler anywhere, when you don't have a real ruler with you!

- Ad free, for real, forever!
- Pick your units: fractional inches, decimal inches, centimeters or millimeters
- Calibrate your ruler with a credit card to get you started anytime, anywhere
- Don't have a credit card with you? Calibrate your ruler with a coin!
- Calibrate your ruler with a real ruler to achieve the best precision in your measurement transfers
- Manually set the ruler to a known length for accurate measurements
- Night mode to save battery (on AMOLED screens) and to relieve your eyes at night
- Save your measurements for future use
- No permission required

Update history:

3.5 -- Millimeters, set to predefined length
3.3 -- Calibrate with a credit card, remove saved measurements from history
3.2 -- Fractional display of measurements in inches
3.0 -- Android Material theme and new scale for measurements in inches
2.1 -- Calibrate with a coin, default calibration button (reset)
2.0 -- You can now save your measurements
1.7 -- Night mode to save battery and/or read more easily at night
1.6 -- Added default calibration for common devices (Nexus series, Galaxy S series, Galaxy Note 1, 2 and 3)

From version Ruler 3.6.5:

Fix issues with tall devices such as the Pixel 2 XL, and devices with a notch a the top of the screen.
Add Swedish krona to available currencies for calibration as well as Swedish localization.
Minor UI improvements.

All versions
Ruler 3.6.5
May 24, 2023


Uploaded:May 24, 2023 at 9:01PM UTC

File size:1.76 MB


Ruler 3.6.2
November 3, 2018


Uploaded:November 3, 2018 at 5:48PM UTC

File size:1.29 MB


Ruler 3.6
December 10, 2015


Uploaded:December 10, 2015 at 2:16PM UTC

File size:1.21 MB