Free Online Timegrapher for Mechanical Watches
Measure your mechanical watch's rate, beat error, and beat rate using just your microphone. No expensive hardware needed — test watch accuracy instantly in your browser.
How a Timegrapher Works
1. Listen to the Ticks
Place your watch near the microphone. The timegrapher captures the tick and tock sounds from the escapement.
2. Analyze the Pattern
Algorithms measure the time between ticks to calculate rate, beat error, and identify the beat rate.
3. Read the Results
See your watch's accuracy in seconds per day, just like a professional watchmaker would measure it.
What is a Timegrapher?
A timegrapher is a tool used by watchmakers to measure the accuracy of mechanical watches. It listens to the ticking sounds made by the watch's escapement mechanism and calculates how fast or slow the watch is running.
Rate (s/d)
How many seconds per day the watch gains or loses. A well-regulated watch runs within -5 to +10 s/d.
Beat Error (ms)
The difference between tick and tock intervals. Lower is better — under 0.5ms is good, under 0.3ms is excellent.
Beat Rate (bph)
Beats per hour — common rates are 18,000, 21,600, 25,200, 28,800, and 36,000 bph.
Amplitude
The arc of the balance wheel swing in degrees. Healthy watches typically show 250°-310°.
COSC certified accuracy
Most common bph
Excellent beat error
Healthy amplitude
Why Use an Online Timegrapher?
Free
Professional timegraphers cost $200-500+. Ours is free.
No Hardware
Just your device's microphone — no piezo sensor needed
Instant
No download, no signup — start measuring immediately
Accurate
Web Audio API provides precise timing analysis
How to Read Timegrapher Results
What does rate (s/d) mean?
Rate measures how many seconds your watch gains (+) or loses (-) per day. A rate of +5 s/d means your watch runs 5 seconds fast per day. Most mechanical watches are considered well-regulated between -5 and +10 s/d. COSC-certified chronometers must be within -4 to +6 s/d.
What is beat error?
Beat error measures the symmetry of the tick-tock sound. In a perfect watch, the tick and tock are equally spaced. Beat error is the difference in milliseconds. Under 0.5ms is acceptable, under 0.3ms is good, and under 0.1ms is excellent. High beat error can affect accuracy and is corrected by adjusting the hairspring stud.
What are common beat rates?
Beat rate (bph) is how many times the balance wheel oscillates per hour. Common rates: 18,000 bph (older/vintage watches), 21,600 bph (many Swiss and Japanese movements), 25,200 bph (some Seiko movements), 28,800 bph (modern standard), and 36,000 bph (high-beat movements like the Zenith El Primero).
What is amplitude?
Amplitude is the angle of the balance wheel's swing, measured in degrees. A healthy watch typically shows 250°-310°. Low amplitude (below 220°) can indicate a dirty movement, weak mainspring, or worn parts. Very high amplitude (above 320°) can cause “knocking” where the impulse pin contacts the wrong side of the pallet fork.
Ready to Test Your Watch?
Know your mechanical watch's accuracy without expensive equipment — just your browser and a microphone.
No download • No signup • No hardware needed