How do you estimate an auto insurance claim?

When an Auto Insurance Claim is estimated a number of things will be taken into account.

In relation to the Car(s) involved.

Age Of Car

Pre-Accident Condition

Market Value at time of Claim

Insurance Cover

Recovery Costs, Storage, repair cost.

Usually if the cost of repair exceeds 60% of it's pre-claim value, then the insurer will "write off" the car - Not repair it. Usually they will then pay the "fair market value". Obviously, what they consider fair, and you consider fair may be completely different. Negotiation.

Never accept the first offer.

Obviously if Injuries are involved, then differing injuries attract differing compensation payouts.

Time is a factor, length of recovery, permanent disabilities, as is severity of Injury, Likely loss of earnings / capacity to earn. Traumatic experience, Whiplash, stress and other things are all contributing factors.

It is very difficult to give even a rough guess as all claims are different, plus, you have to win.