What is the value of a 1957 US cent?

This is considered a common date and is worth about 2 cents regardless of mint mark. Over 1.2 billion were minted between the two mints active at the time, Philadelphia and Denver.

1957 is one of the most common dates for wheat cents. In circulated condition, it's worth about 2 cents. A nice uncirculated one is worth about 25 cents.