Overview

Kerbal Engineer Calculator

Helps determine parts needed for target TWR with best specificity.

    TWR = Thrust / (mass * gravity)
    Isp = Sum(Thrust foreach engine) / Sum(Thrust/Isp foreach engine)
    dV = ln(MassStart / MassEnd) * Isp * gravity

Sources: http://wiki.kerbalspaceprogram.com/wiki/Cheat_Sheet