What a wrecked car is still worth
Damage tends to be concentrated in one area. A car hit in the front can still have a good transmission, rear doors, seats and wheels. Those parts are what lift an offer above scrap value, so describe where the damage is and what still works.
If your insurer declared the car a total loss and you kept it, you may have a salvage title. Mention it when the buyer contacts you, so the offer starts from the right place.
Selling after an insurance payout
If the insurance company paid you and took ownership, the car belongs to the insurer and it decides what happens to it. If you chose to keep the car (owner retention), you can sell it once you have the title or salvage certificate the state issued.
Total loss and keeping the car
When an insurer totals a car, it pays the car's actual cash value. If you decide to keep the car, the insurer usually subtracts what it would have sold the wreck for, and the state brands the title as salvage.
That can work in your favor: if the salvage deduction was low, selling the wreck can bring in more than the insurer subtracted. Check the settlement letter for the salvage figure before you decide.
Flood, fire and hail damage
Hail dents, keyed paint or a cracked bumper mostly affect resale, so a car that still runs can get a decent offer with a dented body. Flood and fire are different because they reach the wiring, the interior and the engine, so those cars are priced closer to their metal value. Choose 'Flood/fire' in the value calculator for a rough figure.
Many states brand the title of a car totaled by water damage as flood or salvage. Selling one privately without saying so can get you into trouble, and buyers often check vehicle history reports anyway. Mention the flood or fire when the buyer contacts you and sell the car as-is.