Artificial Gravity Calculator

Centripetal acceleration equals the square of the angular velocity times the radius, so for any fixed target gravity level, a larger radius needs a proportionally slower rotation rate to produce the same acceleration. This is why large rotating-habitat concepts like the Stanford torus or O'Neill cylinder favor radii of hundreds of meters or more -- at that scale, Earth-equivalent gravity is achievable at a rotation rate low enough to stay comfortable, while a small station would have to spin uncomfortably fast to produce the same gravity level.

In a rotating habitat, acceleration is proportional to distance from the rotation axis, so a crew member's feet (at the habitat floor, farther from the axis) experience slightly stronger "gravity" than their head (closer to the axis). This gradient gets larger as the rotation radius shrinks, because the same height difference becomes a bigger fraction of the total radius -- which is one more reason small-radius rotating habitats are considered less comfortable than large ones even at the same target gravity level.

Much of the discomfort in a rotating habitat comes from the Coriolis effect -- the sideways deflection felt when you move your head or walk while the whole environment is spinning -- and that effect's strength depends on the rotation rate (RPM), not directly on how much gravity the rotation produces. Two habitats producing identical target gravity can feel very different to occupants if one achieves it with a slow spin at a large radius and the other with a fast spin at a small radius, which is why this calculator rates comfort from RPM rather than from the gravity level itself.

No -- the rotation rate is set entirely by the target gravity level and the rotation radius, both of which describe the habitat's overall geometry. Crew height only affects the gravity gradient figure, which measures the difference in effective gravity between a crew member's head and feet at the habitat floor -- a taller crew height produces a larger measured gradient at the same radius, but it has no effect on the RPM required to reach the target gravity in the first place.

No -- algebraically, the gradient percentage works out to exactly crew height divided by rotation radius, with the target gravity level cancelling out completely. That happens because both the head and feet accelerations scale with the same rotation rate, so their ratio depends only on how far apart they are relative to the radius, not on how fast the habitat is spinning or how much gravity that spin produces. A habitat targeting Mars gravity and one targeting Earth gravity at the same radius and crew height will show the identical gradient percentage.