The amount of muscle you can gain naturally in a year depends on several factors, including your starting point, training, and nutrition. Here are some general guidelines:

Beginners: If you’re new to weightlifting, you can expect to make rapid progress during your first year. On average, a natural male lifter might gain about 20 pounds of muscle in their initial year. For women, the rate of muscle growth is similar, but they may gain slightly less due to their smaller frame—around 14 pounds in the first year.

Intermediate Lifters: Even after the initial “newbie gains,” intermediate lifters can still experience impressive muscle growth. By consistently following a structured diet and training program, a 150-pound intermediate fitness enthusiast might gain 10-15 pounds of muscle per year.

Individual Variation: Keep in mind that individual variation exists. Some people may gain more or less muscle based on genetics, body type, and other factors.

Remember, consistency, proper training, and adequate nutrition play crucial roles in achieving your muscle-building goals.