From beginner-friendly picks to power-user tools, our mm ruler screen list covers 237+ iPhone apps updated through November 2026. Compare ratings, prices, and screenshots in one place.
This app provides a highly accurate, actual-size ruler that adapts to any screen. It offers dual-edge measurement, a precision caliper mode, and universal calibration for reliable real-world measurements. It functions offline and is designed for various devices.
Measure lengths, widths, and diagonals accurately using your phone. Switch between metric and imperial units, and utilize flexible starting points for precise measurements in any direction. Features auto-calibration for minimal error and a screen lock to preserve readings.
What We Love
👍 Simple and easy to use
📏 Accurate measurements (for some)
💡 Useful for small objects
✨ Clean interface
🚀 Fluid performance
🛠️ Good basic functionality
Room to Improve
😠 Excessive and intrusive ads
🚫 Ads block measurements
🔊 Loud and shocking ads
💸 No option to pay for ad-free (or purchase lost)
📉 Inaccurate inch measurements (decimal vs. fractional)
What are the best mm ruler screen apps for iPhone?
Ruler: CM, MM & Inches tops our mm ruler screen apps ranking as of November 2026, with a 5.0-star average from 2 App Store ratings, and it's free to download.
Are there free mm ruler screen apps for iPhone?
Yes — 19 of the top mm ruler screen apps we rank are free to download, including Ruler: CM, MM & Inches and Ruler - CM, MM, Inches.
Does Ruler: CM, MM & Inches have ads or in-app purchases?
Ruler: CM, MM & Inches shows ads and offers in-app purchases, according to its App Store listing as of November 2026.
How many mm ruler screen apps are on the App Store?
We track 237+ mm ruler screen apps on the iOS App Store as of November 2026, ranked by rating, recency, and analysis of real user reviews.