It is difficult to quantify at such an early stage of the claims process as no two injuries are ever the same the way people heal also varies.
There are a lot of aspects to consider, for example the other side will try and attribute some contributory negligence to get the value down (and bear in mind I do not know the circumstances so just generalising), but there willl be payments for the injury itself which is called General damages, and then special damages which covers pain and suffering, damage to clothing and other property, loss of earnings, out of pocket expenses and, and, and.
The value of your claim (which is called Quantum) to a large degree wiill be based on the report prepared by the independent medical expert who will look at your medical records and the circumstances of the crash, and report on the injuries sustained and the long term prognosis.
There are guidlines that lawyers, the insurers and the courts work by, and there are upper and lower limits depending on the severity, so as i say it is very difficult apart from unproffesional to suggest a value, but your solicitor should pitch it around the right level if they are experienced and professional.