When determining the amount of compensation for your damages, you never want to calculate them yourself. As mentioned, many damages are non-economic or to compensate for future losses, and you need a legal professional to conduct these calculations.
There are several methods that a lawyer can use to determine the worth of your damages. Your lawyer can help ensure that the damages you list in your claim are reasonable and have supporting evidence. The insurance company will certainly never take your word for the value of your losses, and your attorney can prove them sufficiently.