How to add a forecast: build a view with a date (continuous or discrete date part, but not Exact Date) and a measure → Analytics pane → drag Forecast onto the view (or right-click → Forecast → Show Forecast).
| Setting |
Default / options |
| Model |
exponential smoothing; Automatic · Automatic without seasonality · Custom (trend & season: none/additive/multiplicative) |
| Prediction interval |
95% by default; 90%, 95% or 99% (or none) |
| Forecast length |
automatic, or set exact periods/until |
| Source data |
can ignore the last n periods (e.g. a partial current month) |
| Describe |
right-click → Forecast → Describe Forecast shows the model, AIC and quality |
When forecasting is unavailable: the view has table calculations, disaggregated measures, percent calculations, totals/subtotals, or the date is Exact Date.
Related practice: trend line practice questions · Analytics pane practice questions (2.8) · Data Analyst study guide
FAQ
What forecasting method does Tableau use?
Exponential smoothing, with automatic or custom trend and seasonality.
What is the default prediction interval?
95%. You can change it to 90% or 99% under Forecast Options.
Why is Forecast greyed out in my view?
Forecasting is unavailable when the view has table calculations, disaggregated measures, percent calculations, totals or subtotals, or an Exact Date field.
Sources: How forecasting works · Create a forecast · Describe a forecast
