On most rentals the minimum age is 25 without an additional Age Differential Charge, and 21 with an additional Age Differential Charge. However.Las Vegas Hertz® Car Rental

The minimum age for the Hertz Prestige Collection (HPC) and a few select Fun Collection (HFC) vehicles have a minimum age of 25 to rent.

For more information/cost, click on "Reservations" on the navigation menu on the left hand side.  Next click on "Qualifications & Requirements". 

Then enter pickup location, next choose "Age Restrictions and Exceptions" from the topic drop down menu.