Grade 0 - Tonsils are found confined to the space between the anterior and posterior pillars
Grade 1 - Tonsils are enlarged and is just seen coming out of the anterior pillar.
Grade 2 - The enlarged tonsil reaches to about half the distance of uvula.
Grade 3 - The enlarged tonsil comes into contact with the uvula.
Grade 4 - The enlargement of tonsil is so much that both tonsils lie virtually in contact with each other i.e. kissing tonsils.