First, the right way to do this is to find out what original tire size came on the car. That information will be located on a vehicle tire placard which is usually on a doorpost or in the glove box - but occasionally will be found on the fuel filler door or on the trunk lid.
From that you need to determine what load rating the OEM said was right for the vehicle.
Then look up what fits under the fenders. The easy way to do that is to use Tire Rack’s alternative size for your vehicle. Does one of those sizes fit your wheel? If so, you’re good to go. If not, it might be time for a re-think.
Just be aware that it is load carrying capacity which is the most important thing about tire sizing.