Some states have minimum credit requirements that must be met, while others have very little or no regulation at all. Some states specify credit requirements by subject area (e.g., a certain number of credits in math, science, English, etc.).
To find the answer for your specific situation, you need to:
1. Check your state's homeschooling laws: This is the most crucial step. Your state's Department of Education website will have the specific requirements for graduation.
2. Review your homeschooling program's requirements: If you're using a structured curriculum, it might have its own graduation requirements that need to be met, in addition to (or possibly in place of) state requirements.
Without knowing your state, it's impossible to give you a definitive number of credits.