The calculator is only an approximate. Basically they are averaging what is "normal". It doesn't really say what your specific fish may have. It could be lower or higher. The fish in Pennsylvania is so toxic, that you aren't allowed to eat for more than 1 meal a month in most rivers. Obviously this calculator doesn't account for that.

So I wouldn't depend on that calculator at all. I personally only use Carlson's fish oil/cod liver oil. If you buy it make sure you get it from a store that replenishes their stock constantly or you'll get rancid oil.