I don't put much stock into these type of things besides for just a quick laugh. There are way too many variables in life that can take us out easily. For example, my mom was feeling great until one day she had difficulty breathing. She went to the doctors and after extensive testing she found that she had an auto immune disease with her lungs that was heredity. When she was in her 20s she smoked occasionally, but had quit smoking in her early 3os. She died 5 years later. My father is nearing 80. He eats decently. What is keeping him alive and healthy is he sells icecream on the beach in the summer. He walks like 5-10 miles per day on sand. But, OTOH he is subjected to the intense rays of the sun. Especially from 10am- 3pm. And, he doesn't wear sunscreen.
In conclusion, much of our longevity is part eating healthy and getting enough exercise, but the other part is luck. Your genetics. The danger with these life expectancy calculators is it can lull you into believing that you are invincible, and that you'll live to 100. The truth is there are many things that are outside our control that can easily take us out.