Calculating forecast accuracy and precision

In this Excel tutorial you will teach yourself how to calculate forecast accuracy and precision.

Forecast accuracy and precision are two important metrics in forecasting, and can be calculated in Excel using a few different formulas.

Accuracy refers to how close the forecast is to actual values, and can be measured using the mean absolute deviation (MAD), mean absolute percentage error (MAPE), or mean squared error (MSE).

Precision refers to the variability or uncertainty of the forecast, and can be measured using the mean absolute deviation (MAD) or the root mean squared error (RMSE).

Data preparation

To perform calculations you need data table.

data table to calculate accuracy

Column A is Prediction. Actual value is in column B. In C column you will calculate forecast accuracy using Excel formula.

Forecast calculations

Formula you need here is =IF($A2<$B2;$A2/$B2;$B2/$A2).

Copy it and paste to C2 column. Next drag and drop it down to calculate other values as well.

Final data table looks like here:

accuracy calculated

This way you calculated forecast accuracy and precision in Excel. Thanks to it you can see how how accurate your forecasts were.

Tip: You can use simplier formula: =MIN($A1:$B1)/MAX($A1:$B1)

See also how to use Excel FORECAST function for forecast calculations..