Cross Correlation Lag Calculator
Calculate full finite cross correlation and a signed global-energy-normalized absolute peak lag for two numeric sample records.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Evaluate shifted finite product sums with zero padding and one global record-energy normalization denominator.
Rxy[k]=Σx[n]y[n+k]; coefficient=Rxy[k]/√(Σx²Σy²)
Worked example
For x=[0,1,0,0] and y=[0,0,1,0] without mean removal, the absolute peak is coefficient 1 at lag +1 sample. At 1000 Hz that lag is +0.001 s: y occurs later.
Assumptions and input details
Each record has 2–200 numeric samples at the same sampling rate. Optional demeaning uses each entire record’s own mean; processed energy must be positive. This is not lag-by-lag overlap normalization. The absolute peak may be negative (inversion); ties prefer the smallest absolute lag, then negative before positive. No synchronization correction, significance test or confidence estimate is supplied.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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