Auroguy,

If you want to do the calculations some formula are

Thrust= 2.83e-12 * rpm^2 * Diam^4 (this is a dementional formula you need to use inches for prop Diam

EX: 5x4 prop 12000 rpm

Thrust=2.83e-12* 12000^2 * 5^4
Thrust= .255 pounds

The none dementional formula is

Thrust= Ct * q * RPS^2 * Diam^4

Ct= .0888 is what the thrust programs are using it ranges from about .06 for a low pitch prop to about .12 for higher pitch props.
q=.002378 for sea level
rps= revolutions per sec
Diam= feet

Thrust= .11 * .002378 * 200^2 *(5/12)^4
Thrust=.11 * .002378 * 40000 * .0301
Thrust= .315 pounds