If you have ever looked up the price of silver or gold, you have seen the price quoted “per troy ounce.” But what exactly is a troy ounce, and why do precious metals use a different measurement system from everyday weights? This guide explains all the weight units used in the precious metals world.
What is a Troy Ounce?
A troy ounce is the standard unit of measurement for precious metals worldwide. It is named after Troyes, a city in France that was a major trading centre in the Middle Ages where this weight system was established.
1 troy ounce = 31.1035 grams
This is slightly heavier than the regular (avoirdupois) ounce used for everyday items like food:
1 regular ounce = 28.3495 grams
So a troy ounce contains about 10% more metal than a regular ounce. This distinction matters when calculating the value of silver or gold.
Why Do Precious Metals Use Troy Ounces?
The troy ounce system has been used for precious metals trading for centuries and has become a global standard. When you see a silver price quoted as “$32.36 per ounce,” that always refers to a troy ounce, not a regular ounce.
This standardisation is important for global trade — buyers and sellers in Tokyo, London, Mumbai, and New York all use the same unit, ensuring clarity in international transactions.
Converting Between Weight Units
Here are the key conversions for silver and gold:
| Unit | Grams | Troy Ounces |
|---|---|---|
| 1 Troy Ounce | 31.1035 g | 1 |
| 1 Gram | 1 g | 0.03215 oz |
| 1 Kilogram | 1,000 g | 32.1507 oz |
| 1 Tola | 11.6638 g | 0.375 oz |
| 1 Sovereign | 7.98 g | 0.2566 oz |
| 1 Ratti | 0.1215 g | 0.003906 oz |
Traditional Indian Weight Units for Silver
In South Asia, several traditional units are used alongside metric measurements:
Tola: Equal to 11.6638 grams. This was the weight of one British Indian rupee coin. The tola remains commonly used in India, Pakistan, Bangladesh, and Nepal for buying gold and silver. Silver price per tola in India is approximately Rs. 3,090 at current rates.
Sovereign: Equal to 7.98 grams. Originally the weight of a gold sovereign coin, this unit is still used in parts of South India, particularly for gold jewellery purchases. The equivalent silver value per sovereign is approximately Rs. 2,115.
Ratti: A very small traditional unit equal to 0.1215 grams, approximately the weight of a dried gunja seed. It is rarely used for silver but occasionally appears in traditional jewellery measurements.
Masha: Equal to approximately 0.97 grams. Used in some parts of India for fine measurements of precious metals.
Tael: Used in East Asia, particularly China and Hong Kong. 1 tael = 37.429 grams.
Why Do Silver Prices Per Gram Look So Different from Per Troy Ounce?
This confuses many first-time precious metals buyers. The silver price in per-gram and per-troy-ounce terms should be consistent — just multiply or divide by 31.1035.
If silver is $32.36 per troy ounce:
- Price per gram = $32.36 / 31.1035 = $1.0405 per gram
- Price per kg = $1.0405 x 1,000 = $1,040.50 per kg
Our Silver Calculator at SilverRatesToday.com handles all these conversions automatically. Simply enter your amount in any unit and the calculator converts it instantly to the current market value.
How to Convert Silver Weights at Home
Troy ounces to grams: Multiply by 31.1035 Grams to troy ounces: Divide by 31.1035 Tola to grams: Multiply by 11.6638 Grams to tola: Divide by 11.6638 Troy ounces to tola: Multiply by 2.6667
Use our free Silver Calculator at SilverRatesToday.com for instant conversions between all precious metal weight units in multiple currencies.