Forecast Accuracy

Definition

A measure of how close past forecasts came to the actual values. Computed as the difference between forecast and reality, expressed as a percentage or absolute number. Lower is better.

What it tells you

The retroactive scorecard for your forecasting methodology. A consistently 8% MAPE means you can trust the forecast to within ±8%; 25% means the forecast is unreliable for short-term decisions.

How to track it

Compare past forecasts to past actuals after the period closes. Use MAPE, SMAPE, or MAE.

Where it fits

If you don’t measure forecast accuracy, you can’t know whether your forecasting tooling is helping or hurting. Modern tools publish accuracy reports monthly.