Hi,
2 problems:
1) If I enter "Fuel" amount in litres in the flight details menue, it translates into the same number but in kg. This is done automatically vice and versa and obviously causses a much to high weight, as specific AVGAS weight (0.72) remains unconsidered. Tried a lot in the aircraft profile and Set up section but didn´t finad a solution

2) If I add up the input figures in the W-B section of flight details, SD comes automatically up with a much higher weight (in my last calc + 159,5kg) compared to just adding the numbers manually. Any idea, where the differnece comes from?
Many thanks for your comments, Alex

You need to see what your aircraft fuel setup is, in the Setup -> Aircraft screen. It can be set up to use weight, in which case you enter the weight of fuel directly; or volume, in which case you enter the volume in litres or gallons and SkyDemon converts this to weight automatically.

Can you give an example of the calculations you believe to be wrong? You can expand the fuel required output so that each is itemised.