Visit your state's department of revenue website to research property tax laws in your state. Here, you will find information about your state's property tax rate or information about how to find the vehicle property tax rate in your county. If there is no statewide vehicle property tax, you may need to contact your county's auditor to get your vehicle property tax rate.
Find out the fair market value of your vehicle for the current year. Your county auditor's office/county tax office can give you its assessment of your vehicle's value, which will be used to determine your property tax.
Multiply the tax rate percentage by the assessed value of your vehicle. For instance, if your vehicle's value is assessed at $10,000 and the property tax rate is 5%, simply multiply 10,000 by 5% to get $500, which is what you owe.