How much muscle can you gain in one month by working out?

The amount of muscle you can gain in one month through working out can vary widely depending on several factors, including your genetics, training intensity, diet, sleep, and overall lifestyle. 

It's important to have realistic expectations and not expect drastic changes within such a short time frame.

On average, a beginner to intermediate lifter might be able to gain around 1-2 pounds (0.45-0.9 kg) of muscle per month under optimal conditions. 

This rate of muscle gain can slow down over time as you become more advanced in your training. Keep in mind that these are general estimates and individual results may vary.

Factors that influence muscle gain:

Remember, setting realistic and sustainable goals is important for your overall fitness journey. Unrealistic expectations can lead to frustration or even overexertion, which is counterproductive. 

It's also a good idea to consult with a fitness professional or a healthcare provider before starting any new workout or diet program, especially if you have specific goals in mind.