Earthworks. How do you calculate gravel and excavated soil?

How do you generally calculate here for house, terrace, garage, driveway? House or BP: WxL (+2m scaffolding) x cushion height = tons * compaction factor? 12 x 12 x 0.65 = 93.6 sqm x 3 compaction = 280 tons?

Thanks Osnabrücker
I just read your post about the "volume". So would the volume you mentioned be something like what I meant with the factor in my previous post?
So generally theoretically:
W x L x Cushion height x Volume = Tons gravel or excavated soil (depending on soil moisture)
Theoretically, or am I mistaken here?

How do I find the right cushion height for the terrace, garage, and driveway?

Volume = m3 You are looking for the word "Wichte", t/m3. You can also search on Google what is suggested there. In the "other" forum 2.2 t/m3 is suggested. From me rather 1.8. It also depends on the material.

How do I find the right cushion height for terrace, garage and driveway?

Based on the expert specifications of your appraiser, planner or landscaper.

How do I find the right cushion height for terrace, garage, and driveway?

Depends on your soil. The more frost-sensitive, the deeper. The worse the water drains, the deeper. And the more load (driveway!), the deeper.