How to use the time series calculator
Prepare the values for this calculation
Calculate descriptive time-series mean, linear trend, lag-1 autocorrelation, and trailing moving-average forecast. Use the formula below to check that it answers your question. Read the input units before transferring figures from a statement, measurement or dataset.
Enter and check each input
- Time-series values: use the same separators and value order as the example in the input table. Replace the example data with your own complete dataset.
- Trailing moving-average window: enter a value at least 1 and no more than 1000 and a whole number. Use the unit named in the label or selected above. Do not leave this required field blank.
The input table gives a complete example. Keep units and time periods consistent across related fields.
Calculate and resolve any input error
Choose Calculate after entering the values. Changes also update the answer after a short pause. If an error appears, follow its message, correct the field and calculate again. Reset restores the example values.
Interpret the answer
Check Time-series summary first. With the unchanged example inputs, it is Mean 17; trend 2/period. Compare the additional metrics with the primary result; each has its own label and unit.
Compare and keep a useful result
Read the chart’s axis labels and data table. A scenario curve changes one stated input while holding the others fixed; it does not add external observations. Use Download graph to save an available chart as a PNG.
Use Copy result or Download CSV to keep the answer. Share tool shares the page address without placing your input values in the URL. Recheck inputs and assumptions before using the result for a decision.
Time Series Calculator formula
Trend is OLS of y on t=1…n; lag-1 autocorrelation uses centered adjacent products divided by total centered sum of squares; forecast is the mean of the last selected window.
Inputs and units
| Input | Format / range | Example |
|---|---|---|
| Time-series values | Text / numeric list | 10,12,14,16,18,20,22,24 |
| Trailing moving-average window | minimum 1; maximum 1000; whole number | 3 |
Worked example
Using the example inputs above, the time-series summary is Mean 17; trend 2/period.
- Time-series summary
- Mean 17; trend 2/period
- Mean
- 17
- Linear trend per period
- 2
- Lag-1 autocorrelation
- 0.625
- 3-period moving-average forecast
- 22
Results and assumptions
Descriptive summary only; the moving-average value is a simple one-step forecast and does not model seasonality or structural breaks.
Fix an input or unexpected result
Trailing moving-average window is required. Enter trailing moving-average window using the format and bounds in the input table. Zero and an empty field are different: use zero only if it is allowed and represents your data.
If your answer differs from the example, choose Reset and compare every field, including selected units and options. Check percentage versus decimal entry and whether values describe the same period. Round only the final displayed answer when reproducing the formula.
If a discrepancy remains, report the calculator issue with the page address, non-sensitive example inputs, actual result, expected result and a reference for your calculation.