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

Usable Milliamp Hours (mAh)

Required number input.

Average Milliamps (mA)

Required number input.

Ideal quartz-watch battery life in hours from usable mAh capacity and average mA draw. 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]

Hours (h)

The resulting hours 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.

• Mainspring Turns Power Reserve

  Ideal running hours from usable barrel turns and measured running hours per barrel turn.

• Jumping Hour Advance Rate

  Average jumping-hour advances per day for a specified hours-per-jump interval.

• Alarm Set Offset

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