Check out https://angel.co/salaries

Pick location, market & role. There you can see equity given + salary.

There's a caveat though, if this is you first developer and he/she is going to be essential to your growth maybe you should consider him/her as a cofounder. Any tech business needs a tech cofounder in my opinion.

In that case, a much higher percentage than what you would see for employees should be given out.

What is market telling about ? Search around and you will find.