Calculate spaceplanes Hypothetical payload?

[Arugela]

How could you go about doing this. Which parameters do you need and how hard it is to do. I'm building a cargo plane and I"m stuck trying got figure out the max payload potential to kerbin or minimus etc. I know how to calculate delta V once I"m in orbit and flying in space. But not payload from kerbin to orbit. Particularly with a space plane flying most of the time with jet engines.

I'm using a combined engine type also. Rapiers with Whiplashes to carry load below 10k easier.

Edited November 4, 2016 by Arugela

[GoSlash27]

Arugela,

 There are too many factors to be able to estimate that, but there are a couple different approaches you can use:

1) build your spaceplane proportionally to the desired payload. 1-2 engines per 10 tonnes payload. Total spaceplane mass roughly 4x payload, etc.

2) build a replica of your spaceplane with fuel as payload and launch it. However much fuel is left in orbit is how much payload your plane can handle.

Best,
-Slashy