We’re unable to make a specific recommendation for your event, as the tax-deductible amount is dependent on both the specific details of your event as well as your location.
Generally, the tax-deductible percentage is calculated by subtracting the "commercial value" also known as Fair Market Value (or FMV) of the ticket from the ticket price. The FMV isn’t based on how much the event costs your organization to host; it’s an estimate of how much the event would cost your constituents if they purchased it themselves elsewhere. Even if every part of your event is donated and at no cost to your organization, your attendees receive a tangible benefit from your event.
One way to calculate the FMV of your event is by determining the event’s overall commercial value and then dividing it by the number of attendees (tickets). You can also calculate the FMV by comparing the benefits an individual constituent receives to similar benefits purchased elsewhere.
Then, the tax-deductible amount is the cost of the ticket minus the FMV.
Keep in mind that it’s possible that your ticket price may be less than its FMV. In that case, none of the ticket price will be considered tax-deductible.
An example scenario:
Your organization hosts a golf outing event with dinner at a local restaurant afterward. Tickets cost $500 each, and in your area, the average cost of a round of golf at a private club costs $100 per person ($400 for four people). A meal at a similar restaurant costs approximately $150 per person (or $500 for four people). The tax-deductible amount of a single ticket for one attendee would be $250.
If you sell a ticket for four attendees for $1500, it would be $600.
The IRS also provides specific disclosure guidelines for charitable organizations.