Ring Sizer vs DIAMETRO

Ring Sizer makes finding your perfect ring size fast, accurate, and fun, whether you're shopping for an engagement ring, wedding band, or a gift. MEASURE ANY RING OR FINGER • Place a ring on your screen and match the adjustable circle, or use two-point tap for precision • Measure your finger with the on-screen gauge — just slide to fit • Use your camera to scan a ring or finger for hands-free sizing • Auto-calibrated to your device's exact screen PPI for reliable results BROWSE A CURATED RING GALLERY • Explore 30 beautifully crafted rings in gold, rose gold, platinum, silver, and more • Filter by metal type or gemstone, diamond, sapphire, ruby, emerald, morganite, and others • View each ring up close with detailed descriptions AI VIRTUAL TRY-ON • Take a photo of your hand and see any ring from the gallery on your finger • Powered by AI image generation for photorealistic results • The easiest way to visualize a ring before you buy YOUR SIZING VAULT • Save every measurement with date, method, and notes • Compare sizes side by side to track changes over time • Convert instantly between US, UK, EU, JP, CN, and RU ring sizes BUILT FOR ACCURACY • Automatic screen calibration with known device PPI data • Fine-tune calibration manually with a coin or credit card • Confidence indicator shows how reliable each measurement is • Ring width adjustment recommends sizing up for wider bands Ring Sizer is the only ring size app that combines precise measurement tools, an international size converter, a ring gallery, and AI-powered virtual try-on.

Find your ring size in seconds, right on your iPhone. Place a ring you already own on the calibrated circle, slide until the bubble fills the inside of the ring, and DIAMETRO shows its size in EU/ISO, US, UK, CH and JP, plus the exact diameter and circumference. HOW IT WORKS • Calibrate once with a bank card or a coin for true physical scale • Lay your ring on the screen • Slide until it fits, then save the result DIAMETRO PRO • Finger measurement: enter the circumference of your finger and get a recommended size, with optional knuckle compensation • All accent colors • Unlimited saved measurements • Printable PDF sizer, export and backup (PDF, CSV, JSON) ALSO INSIDE • Light and Dark mode • English, Romanian and French PRIVATE BY DESIGN No account. No tracking. Your measurements stay on your device. Conversions are approximate. Confirm your size with a jeweler before buying.