KSP Unit of Mass

[Captain Sierra]

What unit of mass does KSP use? I know it's tons but is that short tons, long tons, or metric tons. I am trying to calculate the ratio of real mass to ingame mass but I am not sure whether to use metric or SI. I am assuming right now the game uses metric tons since it's marketed international.

[EvilotionCR2]

I think metric.

[aeronaut]

In KSP, 1 ton = 1000 kg

[LeFudge]

Also kN and m/s, metric 4 lyfe