Each thruster's raw lift capacity is max thrust (N) ÷ 9.81 m/s².
Weight-adjusted is for a ship you haven't built yet: since every thruster you add also adds to the ship's
mass, its usable lift is the raw figure minus its own weight. Count is
ceil( input mass ÷ usable lift per thruster ) — the fewest units whose combined usable lift still
covers the mass you entered, once their own weight is accounted for.
Simple is for a ship that's already built and weighed in-game, where the thrusters are already part of
the mass you're entering. Count is just ceil( input mass ÷ raw lift per thruster ), with nothing
extra added on top — avoiding double-counting thrusters that are already on the ship.
Both modes use whichever gravity is selected above — Earth-standard 1g by default. Verdure (the Almagest
system's starter planet) is also 1g. Byblos and Kemik are listed in the dropdown but disabled until their
surface gravity is confirmed; a "Custom" option lets you plug in a multiplier yourself in the meantime.