As Harry Callahan said, "A man's got to know his limitations." You figure the maximum landing weight at your destination, whether it's structural, performance limited or runway limited so you have a number to work back from. As pointed out above, that could affect your TO weight if the planned fuel burn is less than the difference between today's max landing weight and your planned TO weight. Or you could have MEL items that affect the landing, anti-skid inop or ground spoilers inop. You work back your maximum allowable weight.
Actual stopping distance is the distance it takes to stop the aircraft. Required landing distance doesn't show up in the FAA regs but is usually used to describe the distance required for dispatching the aircraft. As such, it is ASD plus .666%. That number has to be
less than the landing distance available.