Ring Sizer & Finger Measure
Engagement Wedding Band Gauge
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Find your perfect ring size in seconds. Calibrated for jewelry-store accuracy. Save unlimited sizes for proposals, gifts & online jewelry shopping. Free trial today!
Find your perfect ring size in seconds with the most accurate ring measurement app for engagement rings, wedding bands, and online jewelry shopping.
Designed to eliminate guesswork when buying engagement rings, wedding bands, or jewelry gifts, this app turns your iPhone into a professional ring sizing tool with device-specific calibration for millimeter-perfect accuracy. The ideal solution for surprise proposals, gift shopping, and online jewelry purchases. Whether you measure an existing ring, size your finger directly, or convert between international standards, every measurement is reliable and confident.
— KEY FEATURES —
• Device-Calibrated Accuracy: Detects your exact iPhone model and applies the correct PPI (pixels per inch) for true-to-life measurements. From 326 PPI on iPhone SE to 460 PPI on iPhone 15 Pro Max, when a 17mm circle is shown, it really measures 17mm on screen. Jeweler-level precision in your pocket.
• Two Measurement Methods: Place an existing ring on your screen and match the inner diameter to the on-screen circle, or measure your finger directly using the visual hand guide with precision crosshairs. Perfect for secret proposal planning or when you have no ring to reference.
• 6 International Size Standards: Instantly converts between US/Canada (3-13), UK/Australia (F-Z), EU/ISO (44-70), Japan/China (4-30), millimeters (14.0-22.3mm), and inches (0.55-0.88 in). Shop confidently on Etsy, Amazon, Blue Nile, Brilliant Earth, or any global jewelry marketplace.
• Save Multiple Ring Sizes: Build a personal collection organized by hand (left/right) and finger (thumb, index, middle, ring, pinky). Add custom titles per entry. Perfect for family gift sizes, jewelry professional client records, or shopping for multiple ring styles.
• Complete Conversion Table: A reference guide showing all 27 ring sizes across every international standard in one scrollable table. Compare standards instantly and verify measurements before purchase.
• Fine-Tune Controls: Plus/minus adjustment buttons allow 0.3mm incremental changes for exact sizing. Animated ring circle and tick marks ensure confident measurements. Works completely offline — measure anytime, anywhere.
— PERFECT FOR EVERY SITUATION —
• Surprise Proposals: Measure your partner's existing ring while they sleep, or discreetly size one of their rings when they are away. Silent measurement with no screenshots or notifications keeps the surprise safe.
• Gift Shopping: Buying rings for birthdays, anniversaries, Christmas, or Valentine's Day becomes stress-free. Save sizes for every family member and friend. Never guess sizes when shopping online or in store.
• Jewelry Professionals: Jewelers, ring designers, and store staff use this app for quick consultations, custom order sizing, and client education. Save unlimited client measurements with custom labels.
• Online Jewelry Shoppers: Shop international jewelry websites without sizing anxiety. The conversion system handles every global standard. Preview your exact ring size visually on screen before purchasing. Prevent expensive returns.
— PREMIUM —
Unlock unlimited potential with Premium. Save unlimited measurements for every finger and every person. Enjoy an ad-free measuring experience. Access priority customer support. Get first access to future measurement tools.
— LEGAL —
Terms of Use: https://leanstudio.asia/terms-of-use
Privacy Policy: https://leanstudio.asia/privacy-policy
— SUPPORT —
Questions, feedback, or feature requests? Contact support@leanstudio.asia. We value your suggestions to keep improving the app.
— GET STARTED —
Combine device-calibrated accuracy, dual measurement methods, and international size conversion in one simple app. No more guessing ring sizes or costly jewelry mistakes — just measure, convert, and shop with confidence. Download today and turn your iPhone into a professional ring sizing tool. Perfect for engagement ring shopping, wedding bands, and jewelry gifts.
Ratings & Reviews
What's New
NEW FEATURES:
• Enhanced finger measurement accuracy
• Improved conversion table with better readability
• Bug fixes and performance improvements
PERFECT FOR:
• Engagement ring shopping season
• Holiday gift buying
• Quick professional measurements
Love the app? Leave us a review!
Need help? Contact support@leanstudio.asia
The developer, LEAN ASIA CO., LTD, 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 Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- LEAN ASIA CO., LTD
- Size
- 16.5 MB
- Category
- Utilities
- Compatibility
Requires iOS 16.0 or later.
- iPhone
Requires iOS 16.0 or later. - Mac
Requires macOS 13.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Contains
Advertising
- In-App Purchases
Yes
- Premium Yearly $24.99
- Weekly $4.99
- Lifetime $49.99
- Lifetime $49.99
- Premium Monthly $19.99
- Premium Yearly $24.99
- Lifetime $49.99
- Copyright
- © 2026 Lean Studio