An hourly rate is only where a charter bill starts. Two quotes for the same trip can look very different simply because one includes these lines and the other doesn't.
Federal excise tax
Domestic charter flights in the US carry a 7.5% federal excise tax on the price of the flight. Some brokers fold it into the number they show you, others add it at the end. Always check which one you're looking at.
Segment fees
A small federal fee is charged per passenger and per flight segment. It's a few dollars each, so it rarely changes a decision, but it explains why the final invoice isn't a round number.
Landing, parking and handling
Airports and the private terminals (FBOs) at both ends charge for landing, parking and handling the aircraft. Busy airports in peak season tend to charge more.
De-icing
On cold mornings, the aircraft has to be de-iced before departure. It's rarely in the first quote, and on a large jet it can add a meaningful amount. If you fly out of a northern airport between December and March, ask about it.
Crew overnight
If you keep the same aircraft for your return a few days later, you pay for the crew's hotel and meals while they wait. Sometimes it's cheaper to let the jet leave and book the return separately.
Minimums
Many operators bill at least one or two hours a day, even when the flight is shorter. On short hops, the minimum often decides the price more than the distance does.
Repositioning
A one-off charter is priced from wherever the aircraft is parked. If it has to fly empty to pick you up, that time is on your bill.
How to compare two quotes
Ask each broker for the all-in total in writing, taxes and fees included, for the same aircraft size and the same dates. Compare only those numbers.
See prices route by route in the route guides, or estimate any trip with the cost calculator.