精準量出你的戒圍 只要幾秒
Ring Sizer 在會自動校準到你 iPhone 的螢幕上測量任何戒指或手指，可在六種國際尺寸系統之間換算，並在下單前讓你看到戒指戴在自己手上的樣子。
iPhone 與 iPad 免費使用 · 需 iOS 17.0 或以上 · 自動校準到你裝置的 PPI
一款清楚知道自己畫在什麼螢幕上的戒圍量測工具
多數螢幕量測工具都假設一個通用像素密度，在大部分手機上都會出錯。Ring Sizer 會先辨識你的裝置，再開始測量。
在螢幕上測量戒指
把戒指放在螢幕上並調整可變圓環，或用兩點輕觸標出內側兩端，讀數更精確。
沒有戒指也能量手指
滑動螢幕上的量規，直到貼合手指根部為止。不必列印、不必用線、不必用尺。
用相機免手動掃描
把相機對準戒指或手，讓 App 替你完成測量。
在繪製之前就已完成校準
Ring Sizer 會辨識裝置型號，並依該螢幕已知的每英寸像素值設定比例。你也可以用硬幣或信用卡微調核對。
六種尺寸系統，離線也能用
在美國/加拿大、英國/澳洲、歐盟/ISO、日本、中國與俄羅斯之間換算，並以公釐檢視直徑與內周長。
看它戴在你自己手上
只要拍一次手部照片，就能用 AI 虛擬試戴體驗圖庫中 30 多款戒指。
測量、換算、瀏覽與試戴
來自 App Store 頁面的六個畫面：測量工具、國際換算器、戒指圖庫與 AI 虛擬試戴。
戒圍換算器
在美國、英國、歐盟/ISO、日本、中國與俄羅斯尺寸之間換算，並以公釐檢視直徑與內周長。
國際戒圍對照表
與 Ring Sizer App 內所用完全相同的換算資料，因此你量出的尺寸與在這裡查到的尺寸永遠一致。
| 美國 / CA | 英國 / AU | 歐盟 / ISO | 日本 | 中國 | 俄羅斯 | 直徑 |
|---|---|---|---|---|---|---|
| 3 | F | 44.0 | 4 | 4 | 44.0 | 14.0 |
| 3.5 | G½ | 45.5 | 5 | 5 | 45.5 | 14.5 |
| 4 | H | 46.8 | 7 | 7 | 46.8 | 14.9 |
| 4.5 | I½ | 48.0 | 8 | 8 | 48.0 | 15.3 |
| 5 | J½ | 49.3 | 9 | 9 | 49.3 | 15.7 |
| 5.5 | K½ | 50.6 | 10 | 10 | 50.6 | 16.1 |
| 6 | L½ | 51.9 | 12 | 12 | 51.9 | 16.5 |
| 6.5 | M½ | 53.1 | 13 | 13 | 53.1 | 16.9 |
| 7 | N½ | 54.4 | 14 | 14 | 54.4 | 17.3 |
| 7.5 | O½ | 55.7 | 15 | 15 | 55.7 | 17.7 |
| 8 | P½ | 57.0 | 16 | 16 | 57.0 | 18.1 |
| 8.5 | Q½ | 58.3 | 17 | 17 | 58.3 | 18.6 |
| 9 | R½ | 59.5 | 18 | 18 | 59.5 | 18.9 |
| 9.5 | S½ | 60.8 | 19 | 19 | 60.8 | 19.4 |
| 10 | T½ | 62.1 | 20 | 20 | 62.1 | 19.8 |
| 10.5 | U½ | 63.4 | 22 | 22 | 63.4 | 20.2 |
| 11 | V½ | 64.6 | 23 | 23 | 64.6 | 20.6 |
| 11.5 | W½ | 65.9 | 24 | 24 | 65.9 | 21.0 |
| 12 | Y | 67.2 | 25 | 25 | 67.2 | 21.4 |
| 12.5 | Z | 68.5 | 26 | 26 | 68.5 | 21.8 |
| 13 | Z+1 | 69.7 | 27 | 27 | 69.7 | 22.2 |
戒圍指南
十六篇逐步指南，涵蓋量出戒圍的每一種方法，以及最容易出錯的每一個環節。
How to measure your ring size at home
Five ways to measure ring size at home, ranked by accuracy, plus the calibration step that decides whether any of them actually works.
Read the guide指南Ring size chart for US, UK, EU, Japan, China and Russia
The complete international ring size chart with millimetre diameters and circumferences, plus how to read it and which column your seller actually means.
Read the guide指南Ring size converter
Convert ring sizes between US, UK, EU/ISO, Japanese, Chinese and Russian systems instantly, plus the millimetre diameter every jeweller can work from.
Read the guide指南How to measure ring size without a ring sizer
The string and paper methods explained properly, including the error each one introduces and the fix that makes a phone screen more accurate than either.
Read the guide指南How to find her ring size without her knowing
Eight ways to get an engagement ring size secretly, ranked by how accurate and how risky each one is, plus what to order when you still are not sure.
Read the guide指南How to measure ring size using a ring you already own
The most accurate at-home method: measure the inner diameter of a ring that fits. Here is how to do it on screen, on paper, and with a caliper.
Read the guide指南How to measure your finger for a ring size
Measure a finger accurately when you have no ring to copy: the on-screen gauge method, the knuckle test, and when to take the reading.
Read the guide指南Virtual ring try-on: see a ring on your own hand
How AI virtual try-on works, what it can and cannot tell you about a ring, and how to shoot a hand photo that produces a genuinely useful preview.
Read the guide指南Average ring size for women and men
The most common ring sizes for women and men, what the distribution looks like, and how to use an average safely when you cannot measure.
Read the guide指南mm to ring size: diameter and circumference converted
Turn a millimetre measurement into a ring size. Full diameter and circumference chart, plus how to tell which of the two your number actually is.
Read the guide指南Printable ring sizers, and why they so often print wrong
How to use a printable ring sizer without the scaling error that ruins most of them, plus the credit-card check that verifies any printed or on-screen scale.
Read the guide指南Men’s ring size chart and how to measure
The men’s ring size chart from US 8 to 13 with millimetres, why men’s bands usually need a size up, and how to measure a man’s finger properly.
Read the guide指南Wide band ring sizing: when to size up, and by how much
Wide bands fit tighter at the same size. Here is the adjustment table by band width, why it happens, and how comfort fit changes the answer.
Read the guide指南Ring sizing when your knuckle is bigger than your finger
Measure both the knuckle and the base, pick a size between the two, and stop the ring spinning. The complete fix for large-knuckle ring sizing.
Read the guide指南Engagement ring size guide
How to get an engagement ring size right when you only get one attempt: secret measuring, what to order if you cannot, and the resize questions to ask first.
Read the guide指南US to UK ring size conversion
Convert US ring size numbers to UK letters and back. Full chart from US 3 to 13, plus the half-letter rule that trips most conversions up.
Read the guide關於戒指、合戴度與尺寸的閱讀
二十篇文章，談決定戒指是否合戴的細節：時間、溫度、指關節、改圍與網購。
The best time of day to measure your ring size
Your fingers change size by up to half a ring size between morning and night. Here is when to measure, and why the evening reading is the one to order against.
Read the articleAccuracyNine ring sizing mistakes that cost people a resize
The nine errors behind most badly fitting rings, from measuring the outside of a band to trusting an unscaled printout, and how to avoid each one.
Read the articleTechnologyHow screen calibration turns a phone into a real ring gauge
Why most on-screen ring sizers are wrong, what pixels-per-inch has to do with it, and how to verify any screen scale with a coin or a credit card.
Read the articleAccuracyString, paper, printout or app: every ring sizing method ranked
Six ways to measure a ring size compared on accuracy, cost and what each one actually gets wrong. The honest ranking, including where apps lose.
Read the articleConversionWhat ring size is 17 mm?
A 17 mm inner diameter is a US 6½. Here is the full decoder for every millimetre measurement between 14 and 23 mm, in every sizing system.
Read the articleProposalsA seven-day plan to get her ring size secretly
A day-by-day plan for finding an engagement ring size without giving anything away, with a fallback for each step that fails.
Read the article- Why the UK uses letters and Europe uses millimetres
- Can you resize a ring?
- Why your wedding band is not the same size as your engagement ring
- Cold hands, wrong size: how temperature changes ring fit
- How tight should a ring be?
- Ring size and pregnancy
- Does losing weight change your ring size?
- Buying a ring online: the sizing checklist
- Comfort fit vs standard fit: which size should you order?
- How to gift a ring when you cannot ask the size
- Your ring arrived and it does not fit. Now what?
- Ring size by hand shape and finger type
- How to photograph your hand for the best AI ring try-on
- Left hand vs right hand: why your ring sizes differ
關於戒圍的常見疑問
如何在家量戒圍？
量一枚已經合戴的戒指內徑，再對照尺寸表：17.3 公釐對應美制 7。如果沒有戒指，就量手指根部的周長。無論哪種方式，都請在傍晚、手部溫暖時量測，並確認所依據的刻度已校準。
戒圍量測 App 真的準嗎？
完全取決於校準。17.3 公釐的圓在 460 PPI 的 iPhone 上是 313 像素，在 326 PPI 上是 222 像素，因此假設單一通用密度的 App 可能差上好幾個尺寸。Ring Sizer 會辨識機型並依已知 PPI 設定比例。量測你已有的戒指時，誤差約為四分之一個尺寸。
沒有戒圍量測工具該怎麼量？
用一條不會伸長的紙條繞住手指根部，標出重疊處，再以公釐量出標記處的長度。這就是內周長，54.4 公釐對應美制 7。不要用線，因為線會伸長，而兩公釐的伸長幾乎就是一個完整尺寸。
平均戒圍是多少？
女性平均為美制 6 至 7（直徑 16.5 至 17.3 公釐），男性平均為美制 9 至 10（18.9 至 19.8 公釐）。售出的女性訂婚戒指多在美制 5½ 至 7 之間。平均值適合用來核對量測是否合理，而不是用來取代量測。
怎樣悄悄得知她的戒圍？
借來一枚她已經戴在正確手指上的戒指，量它的內徑。不到一分鐘，而且這是唯一直接量測目標本身的方法。如果做不到，就把戒指放在信用卡旁邊拍張照，或者問她身邊那位守得住祕密的人。
我需要列印什麼嗎？
不需要。可列印的量尺只有在嚴格以 100% 比例輸出時才有效，而印表機驅動程式經常在未說明的情況下縮放到頁面大小。2% 的比例誤差大約相當於一個完整尺寸。Ring Sizer 直接依你的裝置設定比例，因此不必列印，也不必核對。
一天中什麼時候量最好？
傍晚，室溫環境，手部溫暖時。手指在清晨與受涼後最細，冰冷的手可能量出小一個整號的結果；一天結束時最粗。量三次，取最大的一次。
Ring Sizer 免費嗎？
Ring Sizer 可在 App Store 免費下載，並包含選購的 App 內購買項目。支援搭載 iOS 17.0 或以上版本的 iPhone、iPad 與 iPod touch。