The following is a LIVE editable, spreadsheet that you can use to consider operating costs of a personal aircraft. This sheet will allow a user to consider fixed and variable costs in relation to how much yearly use the aircraft will receive.
If you want to learn more about considering the real costs of aircraft ownership and operation, click Beyond the Purchase Price of an Aircraft – Considering and Calculating the Real Cost of Aircraft Ownership and Operation to see a blog post on the topic.
As you play with this, you can see how based on fixed costs, the more an aircraft is operated per year, the most those costs are amortized over the hourly cost and the lower the hourly cost of operation becomes.
If you are considering purchasing an aircraft, I also encourage you to refer to some of the resources AOPA publishes. A good starting place is the AOPA website Aircraft Ownership page
Note, since this is a live sheet, if multiple people are attempting to access the file at the the same time, you could end up changing numbers at the same time. Sorry for that, but at the moment, this was the quickest way I could put this up on the website as an example or for planning purposes.
Second Note, unfortunately this tool does not work on an iPad.