At least, it's best to go in knowing that that's what it is going to be worth in the end, so that you'll be able to negotiate correctly.
They'll probably quote you a percentage and spin a story that ends with you walking away with a cool quarter million when they exit (assuming their optimistic math works out as expected). That's good, because you know that new startups fail outright roughly 90% of the time, and never pay meaningful equity returns the remaining 10% (with the actual exits that are good for employees living in the rounding error of that last number).
But now you have something with a stated value that you can negotiate away in exchange for additional consideration on top of the market rate they'll need to bring you in. I personally used to prefer trading my options for extra paid vacation.
If they suddenly decide that those options aren't actually worth all that money after all, now that you've decided to trade them away, you can start talking about that 90%/10%/0% outcome breakout above and bring in terms like "hazard pay" to offset the near certainty that you'll be back on the job market in eleven months time.
This may affect their impression of whether you're going to be a "team player" who "shares their vision". Which is fine. You're trading your time for money. If they don't want to do that with you, they can keep looking and hopefully find that idealistic kid they're looking for who can't do simple math in the presence of a happy narrative.
Good luck!
If they have more tech employees, you lose this leverage.
Since AngelList favors early-stage startups, that will give you a good starting point on equity amounts. (tl;dr: do not expect much)
Do you know what a CAP table is? Can you read one? Good your 1/2 way there. If they are brining you on at this point and balk at showing you a CAP table, run the other way.