You can compare them with the original calculations that can be found at https://www.ballonflucht.de/en/ballonrechner.html !

I did compare with the wikipedia article linked in this HN thread. The results were comparable.

Now calculate the necessary rate of fuel burn and fuel requirement for a given trip; tensile and tear strength needed for the balloon material and seams.

Tbf they probably didn't do all these calculations, but should have. They risked their lives by getting some of these things wrong.

Done. Updated: https://balloon-lift-calculator.pagey.site

Thanks..