BJ Novak proves Cadbury Egg's are smaller in the US on April 5th, 2007 episode of Conan O'brien.

One Creme Egg weighs 1.4 oz (40 g) and contains approximately 170 calories (710 kilojoules).While many people feel that the size has diminished since its introduction in 1971, Cadbury maintains "It hasn't—you've just grown up!" However, 1.2 oz (34 g) eggs - made in England but licensed to The Hershey Company - are now appearing on shelves in the United States. [4]