Weight in KSP

[kukidog]

Hi guys,

I'm kinda consufe with wights in KSP.

What is 0.01 ? is it 10kg?

What is 0.1? is it 100kg?

What is 1 ? is it 1000kg?

[Johnno]

Yes, mass is measured in tons, just like your list there. 1 = 1000kg etc.

[700NitroXpress]

You can also check the overall weight of your craft by going to the tracking center while the craft is deployed and clicking the info box.

[SRV Ron]

Mass of your rockets is measured in metric tons. Therefore 0.1 tons is 100 kilograms, 0.01 tons is 10 kilograms, etc...

When building your rocket, all parts have their mass listed in metric ton units.

You can display the total weight with a mod while building, or check in map mode when on the launch pad or in space.

[RockyTV]

Or you can do like me calculating my mass while building the rocket. Just put the displayed value and keep calculating, but remember to type in the displayed value right. That way you'll get your ship's mass in tons.

[Dave Kerbin]

Or you can do like me calculating my mass while building the rocket. Just put the displayed value and keep calculating, but remember to type in the displayed value right. That way you'll get your ship's mass in tons.

I also use this method, both in the VAB and even before to plan out a basic part list. However it can lead to the weight sometimes being more then it actually is; there are a few parts (the strut connector and fuel line to start, but a few surprising ones like the octagonal strut) that have no weight despite one being listed in the tooltip. In fact they not only have no weight they have no drag either as for performance reasons they have been marked as insignificant in the physics engine. However they are already light to begin with, and are usually used in such a way that their total weight is a very small fraction of the crafts total weight. I usually check my final weight on the launchpad.

[Specialist290]

Another trick you can use in conjunction with those already listed: You can multiply the total mass of your ship by 10 (actually 9.8, but 10 is a nice, round number that's easy to remember) to get an estimate of the amount of weight (remember, "mass" and "weight" are different things) you'll need to overcome when placing your engines. The "Max Power" value for each engine that's listed in the VAB will tell you how much force each one generates in thrust, and you can then add your thrust up and compare it against the weight to see if your engines will actually lift the rocket off the launchpad.

Specifically, if you divide your engine's total thrust by your craft's weight on Kerbin (that's where the 9.8 comes into play -- 9.8 m/s^2 is acceleration due to gravity at Kerbin's surface), you'll get what is called a Thrust-to-Weight Ratio, which is a simple way to tell whether your rocket will lift off, and how quickly it will do so. If it's under 1, you won't lift off at all, at least until you've burned off some of your fuel.

[Sirrobert]

Mechjeb has helpfull lists saying exactly how much your rocket weights for each stage, and how much ThursttoWeightRatio it has

[Lojik]

Another great tool is kerbal engineer redux. Very useful for building