Ruler & Digital Caliper
Measuring Tool for Small Items
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Measure small, flat objects with a calibrated ruler or digital caliper. Switch among four unit formats, fine-tune contact points, and keep measurements on your iPhone.
Measure small, flat objects on your iPhone with an edge ruler and two-jaw digital caliper.
On supported iPhone models, start with an approximate device-based screen scale. For a physical check, align a ruler with a 20 mm reference on screen. Lifetime access requires a separate one-time purchase and adds repeated measurements and a session workspace: view a result, use it as a reference, and compare the next object. Results and references remain in the current session.
TWO FOCUSED TOOLS
• Edge ruler with a movable origin and end marker
• Digital caliper with two independently adjustable jaws
• Magnified contact guide for placing markers at object edges
• Fine-adjust controls for small position changes
• Reset markers without resetting calibration
FOUR UNIT FORMATS
• Millimeters
• Centimeters
• Decimal inches
• Fractional inches, rounded to the nearest 1/64
BUILT FOR REAL-WORLD ALIGNMENT
Keep a small object flat against the usable screen edge, move the contact points to its edges, and read the result. Switch tools and units as you work. Use portrait or either landscape orientation, and lock orientation while aligning an object.
PRIVATE BY DESIGN
Measurement values and marker positions are calculated on your iPhone. There is no account, advertising, camera access, or measurement server. Limited privacy-conscious product analytics never include measurement values, marker positions, or calibration data. Calibration and preferences are stored locally.
A PRACTICAL SCREEN TOOL
Results depend on calibration, alignment, display settings, screen protectors or cases, and the object being measured. Recalibrate after changing iPhone or Display Zoom. For important measurements, compare the result with a known physical reference. Ruler & Digital Caliper is not a certified measuring instrument.
Support: https://rulercaliper.app/support
Privacy Policy: https://rulercaliper.app/privacy
Terms of Use: https://rulercaliper.app/terms
Ratings & Reviews
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Choose an approximate screen scale on supported iPhone models, or use a 20 mm ruler reference. View results in a clearer screen, compare measurements within a session with lifetime access (separate purchase required), and use more of your screen in landscape. Improved purchase-screen layout and billing details.
The developer, Yurii Koshkin, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Purchases
- Identifiers
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Yurii Koshkin
- Size
- 5.4 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 43 more
- English, Arabic, Bengali, Catalan, Croatian, Czech, Danish, Dutch, Finnish, French, German, Greek, Gujarati, Hebrew, Hindi, Hungarian, Indonesian, Italian, Japanese, Kannada, Korean, Malay, Malayalam, Marathi, Norwegian Bokmål, Oriya, Polish, Portuguese, Punjabi, Romanian, Russian, Simplified Chinese, Slovak, Slovenian, Spanish, Swedish, Tamil, Telugu, Thai, Traditional Chinese, Turkish, Ukrainian, Urdu, Vietnamese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Lifetime Access $9.99
- Copyright
- © 2026 Yurii Koshkin