What is the size of a human heart?

The average adult human heart weighs between 250 and 350 grams (approximately 9 - 12 ounces). It is around the size of a clenched fist and slightly larger in men than in women. The heart is typically about 12 - 15 centimeters (about 5 - 6 inches) in length, 8 - 10 centimeters (approximately 3 - 4 inches) in width, and 6 - 8 centimeters (2 - 3 inches) in thickness. However, individual variations in heart size may occur based on a person's body size, gender, overall physical development, and certain medical conditions affecting the heart.