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

Uncompressed Millimeters (mm)

Required number input.

Installed Millimeters (mm)

Required number input.

Gasket compression percentage from uncompressed thickness and installed compressed thickness. 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]

Compression Percent (percent)

The resulting compression percent 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.

• Wrist Coverage Percent

  Lug-to-lug watch span as a percentage of wearer wrist width.

• Alarm Set Offset

  Forward minutes from current clock time to an alarm time, wrapping at 24 hours.

• Amplitude Decline Power Reserve

  Observed linear balance-amplitude decline in degrees per hour over a running interval.