Until the collection has minted out, calculating exact rarity will be an estimate
This will be available when the collection has minted out, however below are graphics which give an overview of rarity.
Rarity is a percentage value which is calculated by adding up the % below and treating the sum as 100%. For example:
50 + 50 + 50 + 50 + 50....
Out of 100%:
(50/1,000)*100 = 5% chance of 1 variant