Depends on how much you need to earn every month for your expenses, and your skill/experience level. If you need to make $1K a month and do 10% a month then you’ll need $10K capital. If you’ve been trading for a while, get your account signed up on fxblue or myfxbook and take a good look at your stats to get some probabilitistic expectation of what your performance might be.
If you can do better than that you’ll need much less capital. I’ve had a great streak of luck lately on an account I started exactly one month ago. I made $4,750 on $3,000 capital. Best performance of my 2 year forex journey. This kind of performance is probably not going to be sustainable every month, but we’ll see. Something to think about. Gilas Trading Journal