The more correct sounding to me would be: "How much do you weigh?" Or "What is your weight" "Weight" is a noun, whereas "weigh" is a verb, (I believe (?)$. So you would phrase the questions differently. Although I think most English speakers would completely understand and not question your original sentence.

As you may know, unless you're someone's doctor, it is considered rude to ask about someone's weight. But if you did, "how much do you weigh?" would be the way to do it.

I think "How much do you weight" is most common.

My weight about 73 kg