Use this horology calculation to interpret a stated watch, clock, timing-machine, water-resistance, alarm, or historical respiratory-timing quantity under its defined convention.

Driving Teeth

Required integer input.

Driven Teeth

Required integer input.

Driven rotational speed divided by driving rotational speed for one meshing gear pair. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Speed Ratio

The resulting speed ratio returned as a number.

• Mechanical-watch amplitude and beat measurements depend on lift angle, position, state of wind, movement condition, instrument setup, and elapsed sampling. ATM markings are test-pressure classifications rather than literal safe diving depths.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Confirm movement specifications and measure in multiple positions and power states; follow the manufacturer's water-resistance guidance and obtain pressure testing after case service.

• Center To Escape Ratio

  Rotational speed ratio across two gear stages from driving and driven tooth counts.

• Motion Works Ratio

  Rotational speed ratio across two motion-works gear stages from tooth counts.

• Third Wheel Speed

  Driven wheel revolutions per minute from driving wheel speed and mating tooth counts.