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Sample Clock Drift Calculator
Estimate sample-count and nominal-playback duration differences caused by a constant relative recording clock error.
Elapsed real time (min): 0.1–1440; Relative clock error (ppm): -1000–1000; Nominal sample rate (Hz): 8000–384000
Inputs stay on this page and clear on refresh.
Sample Clock Drift Calculator
Elapsed real time (min): 60 Relative clock error (ppm): 50 Nominal sample rate (Hz): 48000
- Sample clock rate error (Hz)
- 2.400000
- Extra/missing samples
- 8640.000000
- Playback duration difference (ms)
- 180.000000
- Playback duration difference (s)
- 0.180000
Define relative ppm = (actual sample clock−nominal rate)/nominal rate × 10⁶. Enter 0.1–1440 elapsed real minutes, −1000 to 1000 ppm and integer nominal rate 8000–384000 Hz. Rate error = rate×ppm/10⁶; extra/missing samples = minutes×60×rate error; playback duration difference = minutes×60×ppm/10⁶ seconds. Multiply by 1000 for ms. Example: 60 min, +50 ppm and 48000 Hz give +2.4 Hz, +8640 samples and +180 ms. A positive clock error captures more samples and makes nominal-rate playback longer for the same real recording interval. Negative means fewer/shorter. Fractional sample results describe a model, not a sample boundary. Six decimals; tiny signed values round to zero. Assumes a constant average error; excludes clock wander, dropouts, resampling and synchronization corrections. No clock measurement, timecode conversion or automatic correction; verify actual devices and sync references.
Methodology
How it works
Define relative ppm = (actual sample clock−nominal rate)/nominal rate × 10⁶. Enter 0.1–1440 elapsed real minutes, −1000 to 1000 ppm and integer nominal rate 8000–384000 Hz. Rate error = rate×ppm/10⁶; extra/missing samples = minutes×60×rate error; playback duration difference = minutes×60×ppm/10⁶ seconds. Multiply by 1000 for ms. Example: 60 min, +50 ppm and 48000 Hz give +2.4 Hz, +8640 samples and +180 ms. A positive clock error captures more samples and makes nominal-rate playback longer for the same real recording interval. Negative means fewer/shorter. Fractional sample results describe a model, not a sample boundary. Six decimals; tiny signed values round to zero. Assumes a constant average error; excludes clock wander, dropouts, resampling and synchronization corrections. No clock measurement, timecode conversion or automatic correction; verify actual devices and sync references.
Method and assumptions documented by Techrider.live
2026-10-19
Frequently asked questions
What should I enter for two independent recorders?
Use their relative error, not both absolute ppm values added blindly. If ppm values share one reference, subtract them in the chosen order; the sign and results follow that order. Shared clocking and timecode are different functions.