The weight of one round for Big Bertha can vary depending on the specific type of round being referred to. However, rounds used by the German howitzer Big Bertha during World War I typically weighed approximately 820 kilograms (1,800 pounds).
Big Bertha is a name used to refer to various large artillery guns, tanks, and golf clubs. Without specifying which Big Bertha you are referring to, it is difficult to provide an accurate answer to your question. Could you please provide more specific details?
