What Is a Watch Balance Wheel and How Does It Regulate Time?

The Heartbeat of Your Watch

The balance wheel oscillates back and forth at a precise rate, dividing time into equal intervals.

How It Works

1. The mainspring provides energy through the gear train
2. The escapement releases energy to the balance wheel
3. The balance wheel oscillates back and forth
4. Each swing advances the gear train by one tooth

Oscillation Rate

What Affects Accuracy

• Position: watch runs differently face up vs face down
• Temperature: extreme cold or heat affects the hairspring
• Magnetism: magnets disrupt the balance wheel
• Power reserve: low power means less stable oscillation