![A replica of the International Prototype Kilogram is pictured at the International Bureau of Weights and Measures (BIPM) in Sevres near Paris, France, November 14, 2018. REUTERS/Benoit Tessier Stock Photo - Alamy A replica of the International Prototype Kilogram is pictured at the International Bureau of Weights and Measures (BIPM) in Sevres near Paris, France, November 14, 2018. REUTERS/Benoit Tessier Stock Photo - Alamy](https://c8.alamy.com/comp/2CRM0DF/a-replica-of-the-international-prototype-kilogram-is-pictured-at-the-international-bureau-of-weights-and-measures-bipm-in-sevres-near-paris-france-november-14-2018-reutersbenoit-tessier-2CRM0DF.jpg)
A replica of the International Prototype Kilogram is pictured at the International Bureau of Weights and Measures (BIPM) in Sevres near Paris, France, November 14, 2018. REUTERS/Benoit Tessier Stock Photo - Alamy
![The International Bureau of Weights and Measures, Sevres, France - Historic Images - NIST Digital Archives The International Bureau of Weights and Measures, Sevres, France - Historic Images - NIST Digital Archives](https://nistdigitalarchives.contentdm.oclc.org/digital/api/singleitem/image/p16009coll19/249/default.jpg)
The International Bureau of Weights and Measures, Sevres, France - Historic Images - NIST Digital Archives
![Er Ashish K Singh on Twitter: "The kilogram is the SI base unit of mass and is equal to the mass of the international prototype of the kilogram , a platinum-iridium standard Er Ashish K Singh on Twitter: "The kilogram is the SI base unit of mass and is equal to the mass of the international prototype of the kilogram , a platinum-iridium standard](https://pbs.twimg.com/media/DaqJWYlX0AE85Eh.jpg)
Er Ashish K Singh on Twitter: "The kilogram is the SI base unit of mass and is equal to the mass of the international prototype of the kilogram , a platinum-iridium standard
![Rear View Of International Bureau Of Weights And Measures High-Res Stock Video Footage - Getty Images Rear View Of International Bureau Of Weights And Measures High-Res Stock Video Footage - Getty Images](https://media.gettyimages.com/id/810773292/video/rear-view-of-international-bureau-of-weights-and-measures.jpg?s=256x256&k=20&c=IZvgr8gKWU6M_n74qrDKH972Q3CZtG5iZ8I-8vmnUjs=)
Rear View Of International Bureau Of Weights And Measures High-Res Stock Video Footage - Getty Images
![A replica of the International Prototype Kilogram is pictured at the International Bureau of Weights and Measures (BIPM) in Sevres near Paris, France, November 14, 2018. REUTERS/Benoit Tessier Stock Photo - Alamy A replica of the International Prototype Kilogram is pictured at the International Bureau of Weights and Measures (BIPM) in Sevres near Paris, France, November 14, 2018. REUTERS/Benoit Tessier Stock Photo - Alamy](https://c8.alamy.com/comp/2CRWP0X/a-replica-of-the-international-prototype-kilogram-is-pictured-at-the-international-bureau-of-weights-and-measures-bipm-in-sevres-near-paris-france-november-14-2018-reutersbenoit-tessier-2CRWP0X.jpg)
A replica of the International Prototype Kilogram is pictured at the International Bureau of Weights and Measures (BIPM) in Sevres near Paris, France, November 14, 2018. REUTERS/Benoit Tessier Stock Photo - Alamy
![The International Bureau of Weights and Measures (BIPM) at Sèvres made 31 prototype line standards..., Stock Photo, Picture And Rights Managed Image. Pic. MPN-267957 | agefotostock The International Bureau of Weights and Measures (BIPM) at Sèvres made 31 prototype line standards..., Stock Photo, Picture And Rights Managed Image. Pic. MPN-267957 | agefotostock](https://previews.agefotostock.com/previewimage/medibigoff/1645dddee373495f828e2ec80462597f/mpn-267957.jpg)
The International Bureau of Weights and Measures (BIPM) at Sèvres made 31 prototype line standards..., Stock Photo, Picture And Rights Managed Image. Pic. MPN-267957 | agefotostock
![International Bureau of Weights and Measures (BIPM) has decided that the kilogram will no longer be pegged to this cylinder made of 90% platinum and 10% iridium. International Bureau of Weights and Measures (BIPM) has decided that the kilogram will no longer be pegged to this cylinder made of 90% platinum and 10% iridium.](https://vajiramandravi.s3.us-east-1.amazonaws.com/media/2018/12/22/9/9/24/252525.jpg)