So up until now I've been playing KSP without ever knowing how much deltaV my rocket had. I didn't see anything wrong with that. Until recently after I flew a mission to Duna. My fuel was low and my first launch window for Kerbin required a lot of deltaV so I waited years for a smaller burn only to discover that I had plenty of remaining fuel to make that first burn. In the end what would have been a 2.5 year mission ended up taking nearly 5 years all because of my faulty guessing. Feeling like a failure, I looked up how to calculate the deltav and then wrote a simple program in c++ that calculates how much deltaV a rockets current stage has. Here's the C++ code: #include <iostream> #include <math.h> using namespace std; int main() { double totalMass, fuelMass, engineVelocity, deltaV, Isp; cout << "What is the total mass?" << endl; cin >> totalMass; cout << "What is the fuel mass alone?" << endl; cin >> fuelMass; cout << "What is the engines Isp?" << endl; cin >> Isp; engineVelocity = 9.8 * Isp; deltaV = engineVelocity * log(totalMass / (totalMass - fuelMass)); cout << "The DeltaV is " << deltaV << "." << endl; cin.get(); cin.get(); } After building this and using this little calculator for a few missions, I now feel idiotic for not doing this before. Until now I never realized just how big of a handicap I had been playing with. So in conclusion I now strongly believe that the deltav for rockets is the single most crucial peace of information missing from the stock game. In the least a level 5 pilot or engineer should be able to calculate the remaining deltav for the current rocket stage. Which could keep players like me all stock. And I have to ask if anyone else thinks Squad should add such a feature to the game.