Air at STP masses 0.077345 pounds per cubic foot.
Hindenburg carried a gas volume of 7,062,000 cubic feet.
Filled with vacuum that’d lift 546231.6 pounds (273 tons).
7,062,000 cubic feet of is 199,973,571 liters.
At STP, that’s 8,927 moles of gas.
8,927 moles of H[sub]2[/sub] masses 17,854 grams-> 39.3 pounds.
8,927 moles of He masses masses 35,708 grams -> 78.7 pounds.
546231.6 - 39.3 = 546,192.3 pounds = Hydrogen filled Hindenburg lift capacity.
546231.6 - 78.7 = 546152.9 pounds = Helium filled Hindenburg lift capacity.
The above assumes zero mass lift bags, and structure for the Zeppelin. Regardless, modern matterials can probably trim off more than the 39 pound lift deficit incurred by using helium rather than hydrogen.