Our rarity rankings help you assess the rarity, and therefore the value, of NFTs compared to other items within the same collection, with one simple score.
How Kalao calculates rarity rankings
NFTs usually come with different attributes, also called "properties".
For example, NFT#5409 in the Crypto Dickheads collection has the following properties:
Simply by looking at the different properties, you will be able to notice that some of them carry rarer traits than others. Since an NFT regularly contains many attributes, in order to compare it to the other NFTs in its collection, it is necessary to combine all these characteristics into a value that we call the rarity score.
Calculating the rarity score
First, we calculate the rarity score of each property.
[Rarity Score for a Trait Value] = 1 / ([Number of Items with that Trait Value] / [Total Number of Items in Collection])
Because [Number of Items with that Trait Value] / [Total Number of Items in Collection] is the same as the trait rarity (fractional, not %), we can also say that:
[Rarity Score for a Trait Value] = 1 / [Trait Rarity of that Trait Value]
2. Then, we sum up the rarity scores over all properties of the NFT. This determines the global rarity score of the NFT.
Now we can compare the global rarity scores of each NFT within a collection to build a ranking
You can find the rarity rank of an NFT on the collection page. Furthermore, you can sort NFTs by rarity.