Home » How to Calculate SMAPE in Excel (With Examples)

How to Calculate SMAPE in Excel (With Examples)

by Tutor Aspire

The symmetric mean absolute percentage error (SMAPE) is used to measure the predictive accuracy of models. It is calculated as:

SMAPE = (1/n) * Σ(|forecast – actual| / ((|actual| + |forecast|)/2) * 100


  • Σ – a symbol that means “sum”
  • n – sample size
  • actual – the actual data value
  • forecast – the forecasted data value

The smaller the value for SMAPE, the better the predictive accuracy of a given model.

The following step-by-step example explains how to calculate SMAPE in Excel.

Step 1: Enter the Data

First, we’ll enter some fake data for the actual sales and the forecasted sales during 12 consecutive sales periods for some company:

Step 2: Calculate the SMAPE Differences

Next, we’ll calculate the SMAPE difference for each sales period using the following formula:

Step 3: Calculate SMAPE

Lastly, we’ll use the following formula to calculate SMAPE:

SMAPE in Excel

The SMAPE for this particular model turns out to be 9.89%.

Additional Resources

How to Calculate MAPE in Excel
How to Calculate MAE in Excel
How to Calculate RMSE in Excel

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