The standards of gold bars include the following aspects:

* **The weight standard of gold bars. **According to the national standard GB/T 26021-2010, the weight standards of gold bars are 500 grams, 100 grams, 50 grams, etc. The most common is the 100 gram gold bar.

* **Purity standard for gold bars. **The purity standard for gold bars is 99.99% gold content.

* **Size standard for gold bars. **The most common size standard for 100g investment gold bars is 60mm in length and 16mm in width.

Different regions and institutions may have different standards for gold bars. For specific circumstances, you need to refer to the "Gold Bar Industry Standards" promulgated by the gold product quality supervision and inspection center of the local or corresponding institution.