Indian vs US Ring Sizes: How to Convert Them
Do not convert an Indian ring-size number to a US number by adding or subtracting a fixed amount. Start with the inside diameter or circumference, then compare that measurement with the chart used by the seller you plan to buy from.
Quick answer
Keep the original size system, find its stated millimetre measurement and match that measurement to the destination seller’s chart. The examples below compare two named published charts. They are reference matches, not a universal conversion rule for every Indian and US ring.
A small, traceable comparison
The Indian-side labels below use diameters in Tanishq’s published guide. The US-side labels use the same listed diameters in Tiffany’s size guide.
| Tanishq guide label | Shared listed inside diameter | Tiffany US label |
|---|---|---|
| 12 | 16.5 mm | 6 |
| 13 | 16.9 mm | 6.5 |
| 14 | 17.3 mm | 7 |
| 17 | 18.1 mm | 8 |
| 18 | 18.5 mm | 8.5 |
| 22 | 19.8 mm | 10 |
| 25 | 20.6 mm | 11 |
Start with diameter in millimetres
Find it in each named chart
Treat the comparison as an estimate
These rows were selected because the listed diameters match. They do not establish the fit of a particular Aagrah ring. Use the seller’s own product guidance for an order.
Work through a conversion
Suppose a ring was sold as size 14 under the Tanishq guide and its listed inside diameter is 17.3 mm. Tiffany’s guide associates 17.3 mm with US 7. That gives you a reference comparison between those charts.
Before ordering elsewhere, check whether the new seller also uses 17.3 mm for its selected label. If the measurement differs, use the new seller’s guidance and consider a fitting.
The important information to carry forward is “17.3 mm inside diameter, based on this chart”, not just “14 equals 7”.
Keep diameter and circumference separate
Diameter crosses the inside opening of a round ring. Circumference goes around it. A 17.3 mm diameter corresponds mathematically to about 54.35 mm circumference, using π × diameter.
That calculation does not prove the finger will fit the ring. It also does not add accuracy to a rough ruler reading. Write the method and unit beside the number.
Why a one-step formula can fail
Size systems use different labels and intervals, and published charts can round measurements differently. Product shape adds another practical question. A wide or unusually shaped ring may feel different from the narrow ring you used as a reference.
For the source chart and more measurements, see the Indian ring-size chart guide. If you need a fresh measurement, follow measuring at home or ask a jeweller.
Use a calculator as a helper
Aagrah’s ring-size calculator can be part of your comparison. Select the correct input system or measurement, keep the original value and check the result against the product guidance. This editorial package has not independently calibrated the calculator’s conversion table.
FAQs
Can I convert from a photograph of a ring?
An ordinary photograph does not provide a dependable physical measurement. Measure the ring itself or use a known size from a named seller.
What if two charts disagree by half a size?
Compare their millimetre values and ask the destination seller about the exact design. Do not average the labels.
Do adjustable rings need conversion?
You still need to compare your measurement with the maker’s stated range. Adjustable-ring fit limits explains the process.