Ask HN: Appropriate Equity for Contractor?

Hi,

We are a basement level startup that has started to get front-end development help on a contractor/part-time basis from someone I know from earlier in my career. We are trying to figure out the appropriate amount of equity to give the front-end dev, as well as how any such grant should be structured.

For example, do we do something like .25% vesting over 6 months so long as he puts in 10 hours per week?

Thanks