Coriolis Effect Calculator
The Coriolis effect calculator can find the inertial force acting on moving objects in a rotating reference frame.
The formula
a = 2Ωv sin φ, with Ω the rotation rate and φ the latitude
Not a force, and not what spins your bathwater
In a rotating frame a freely moving object appears to curve sideways. Nothing pushes it: the ground beneath is turning while the object travels in a straight line as seen from space. Treating the apparent deflection as a force gives correct answers within the rotating frame, which is why meteorology uses it constantly.
The horizontal effect depends on sin of the latitude, so it vanishes at the equator and is strongest at the poles. In the northern hemisphere the deflection is to the right of the direction of travel, in the southern to the left — which sets the rotation direction of cyclones in each hemisphere.
The acceleration is minute, a few millionths of g at walking pace, so it only matters when it acts over hours and hundreds of kilometres. That covers ocean currents, weather systems and long-range ballistics, and emphatically does not cover a draining bath, where the effect is swamped by the shape of the basin and residual motion in the water by many orders of magnitude.