What is a 1918 s penny worth?

The value of a 1918-S penny, which is a Lincoln penny minted in San Francisco, can vary based on its condition and rarity. In general, it is worth anywhere from a few dollars in lower grades to several hundred dollars for those in better condition or with higher grades, such as MS (Mint State). Key factors influencing its value include its grade, whether it has been cleaned or altered, and current market demand. For an accurate assessment, it's best to consult a coin dealer or use a coin grading guide.