Fuel Calculations for Math Losers

[CommissarZach]

So I've been playing this game a while now but being someone who sucks at math I have always just sort of guessed how much fuel a craft needs. This has led to some rather unfortunate kerbals drifting endlessly through space and I would like to change that. I know there are calculations regarding delta-v, gravity, and fuel but my attempts to understand them have fallen flat. Is there a calculator online or some basic rules someone can suggest to me?

[astropapi1]

Just use the Kerbal Engineer Redux, no number crunching required.

[CalculusWarrior]

Mechjeb also has a delta-v readout, but I prefer Engineer; it provides just so much more data.

[Fleb]

Bob Fitch just did a video on this.

I just use a chart to see whats needed, and then Kerbal engineer to show me the crafts delta-v. I have calculated it by myself before, but it takes me hours to build a rocket then lol.

http://wiki.kerbalspaceprogram.com/w/images/7/73/KerbinDeltaVMap.png

[Silverchain]

Rule of thumb - if your craft has about three times as much fuel as it does payload then its delta-v is about 10 times the specific impulse of its engine.

[CommissarZach]

Many thanks guys, and even more thanks from my kerbals who's survivability just shot up about 100% XD

[TimePeriod]

I just guesstimate every now and then. I know how much fuel one engine can lift and then simply add or subtract a number of fuel tanks to increase total payload into orbit.

[Felsmak]

I always guess. I'm actually pretty good at it.