Use Smartphone Measurement Apps

Most modern smartphones include a built-in measurement app that uses the camera and AR to estimate distances and object dimensions with reasonable accuracy.

Steps

1. Open your phone's measurement app -- Measure on iOS (pre-installed), or Google Measure / a third-party app on Android.
2. Point the camera at a flat surface and let the app calibrate.
3. Tap the start and end points of what you want to measure.
4. Read the estimated measurement on screen.

Tips

• Works best on flat, well-lit surfaces with visible texture.
• Typical accuracy is within 1-5% for objects under 10 feet, but varies by phone hardware and lighting.
• Treat results as estimates; not suitable for precision cuts or critical dimensions.
• Phones with LiDAR (iPhone Pro models, some Android flagships) give noticeably better accuracy.