Can someone help me with a quick grammar question?

It could be “a twenty-dollar hourly charge” or “an hourly charge of twenty dollars”.

Thanks so much, bob.

I agree with @bob_‘s answer.

Agreed. That’s three grammarians in concord.

From what I have been able to find I believe both are exceptable but twenty dollar hourly charge is more common, it flows better too. You might consider twenty dollar an hour charge also.

I disagree, for what do you need a hyphen in that spot?

Are we confusing with a compound number situation, like twenty-two dollar hourly charge?

If you want to get really clear call it a “twenty dollars per hour charge”.

@dabbler It’s because “twenty-dollar” is functioning as an adjective (what kind of hourly charge?) rather than a noun. Like a six-foot board or a four-year-old child.

except: to omit or exclude
accept: to receive with approval; consent to