What is binary numeric promotion states?

Binary numeric promotion implicitly applies appropriate widening primitive conversions so that a pair of operands have the broadest numeric type of the two, which is always at least int. Given T to be the broadest numeric type of the two operands, the operands are promoted as follows under binary numeric promotion.

If T is broader than int, both operands are converted to T; otherwise, both operands are converted to int.

This means that byte, short, and char are always converted to int at least.