After the repairs are finished, you may utilize a third-party service like Kelley Blue Book to determine the market worth of your car. Their calculators do all of the math for you. Simply input the vehicle's make and model, year, mileage, and the degree of the accident damage.
You may also contact your own agent and ask for assistance, even if you aren't submitting a claim with them.
You might also hire a lawyer to assist you in managing the process and obtaining a fair settlement. However, this makes sense only if you possess a high-end vehicle that has been severely damaged in an accident.
The information in this answer is general in nature and is not legal or insurance advice for your specific situation. Policy language varies carrier by carrier; your declarations page is the final word. If you're unsure, call your agent before you need to file.