Photograph the surface
Place your reference stick with red ends and a checker border flat against the wall, door, or window. Take a clear photo with even lighting and a moderate viewing angle.
Single-view planar metrology · Android · Free
Measure with your phone.
One photo. Real numbers.
Photograph a flat surface with a red-white reference stick. Mark all four corners of the object and all four corners of the stick. Metrologist returns width, height, area, diagonal, and angles. No internet needed. Ever.
How it works
Three steps from photo to measurement
Mark corners + stick
Drag the green box around your object's four corners and the red box around the reference stick. Pinch-zoom and the built-in magnifier let you land precisely on each point. Enter the stick's length and width in the app settings.
Read the results
Width, height, area, diagonal, and corner angles, with a confidence score. No server call. No account. Works entirely offline.
Features
Built for people who care about accuracy
Real-world units
Results in centimetres, inches, or metres. Set once, never touched again.
Works offline
All computation happens on-device. No internet, no cloud, no account required.
Confidence score
Every result has a confidence score. You know immediately whether to trust the number or retake the photo.
Walls, doors, windows
Any flat planar surface. The geometry engine handles the perspective math; you just tap.
Pinch-zoom magnifier
A built-in magnifier for precise corner placement, even on small details in the photo.
100% unit-tested engine
The Kotlin measurement engine is unit-tested end to end. Results you can rely on, not just hope for.
Accuracy
How close does it get?
±1–5%
Typical error range
92% conf.
Single-view planar metrology works from one photograph. No laser, no tape. Error typically falls between 1 and 5%, depending on photo quality, perspective angle, and how carefully you place the reference stick. For most DIY and trade tasks (cutting materials, ordering tiles, quoting jobs) that's more than enough. The on-screen confidence score tells you when a reading is solid and when it's worth retaking the photo.
Open Source
Free, transparent, and open
Apache-2.0 License
Metrologist is open-source. The measurement engine, the UI, the tests: all on GitHub. Use it, fork it, learn from it. Contributions welcome.
Built by Cocode · Created by Babak Bandpey · View on GitHub →