Triple Exponential Smoothing Forecast Calculator With Chart (Holt-Winters Method)

Last updated on by Editorial Staff

Triple Exponential Smoothing Forecast Calculator

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Quick Guide to Use this Calculator

  • Fill in the required input fields: Actual Demand (Yt), Prior Period Level (L(t-1)), Prior Period Trend (B(t-1)), Seasonality Index (S(t-p)), Level Smoothing Coefficient (α), Trend Smoothing Coefficient (β), and Seasonality Smoothing Coefficient (γ).
  • Click on the “Calculate” button to generate forecasts and estimations.
  • Again to calculate the forecast for the next period, input the current data value, smoothing factors, smoothed level value, smoothed trend value, and seasonality factor (Refer to the table to input the smoothed level value, smoothed trend value, and seasonality factor).
  • Click the ‘calculate’ button. Don’t click the reset button, until you get the forecast for your desired number of periods.
  • Continue the same process to get the forecast for the ‘n’ number of periods.
  • You will get the graphical representation of variations from one period to another and get all the results in the table.
  • You can reset the calculator using the “Reset” button.

Input Field Details

  • Actual Demand (Yt): Current demand in units.
  • Prior Period Level (L(t-1)): Level estimation from the previous period.
  • Prior Period Trend (B(t-1)): Trend estimation from the previous period.
  • Seasonality Index (S(t-p)): Seasonality factor from a corresponding period.
  • Level Smoothing Coefficient (α): Weightage for level smoothing.
  • Trend Smoothing Coefficient (β): Weightage for trend smoothing.
  • Seasonality Smoothing Coefficient (γ): Weightage for seasonality smoothing.


Forecast for the next period, Ft+1 = [Lt + Bt] X St

Level Estimation For the Current Period, Lt = α (Yt/St-P) + (1-α)(Lt-1 + Bt-1)

Trend Estimation for the current period, Bt = β [ Lt – Lt-1] + (1-β) [ Bt-1]

Seasonal factor St = γ [Yt/Lt] + (1-γ) S(t-p)


  • Lt is the value of the level in the time series t
  • Bt is the trend of the series at time t. It indicates the trend is increasing or decreasing  
  • St is the seasonality index at time t
  • St-p is the seasonality index, p periods ago or corresponding seasonality factor
  • Yt is the actual demand at time t
  • α is level smoothing coefficient
  • β is trend smoothing coefficient
  • γ is seasonality smoothing coefficient
  • Lt-1 is the prior period level
  • Bt-1 is the prior period trend

What is Triple Exponential Smoothing?

Triple Exponential Smoothing, also known as the Holt-Winters method, is a time series forecasting technique that considers three aspects: level, trend, and seasonality.

Who Can Use This Calculator?

Individuals, businesses, and analysts involved in forecasting future demand or trends can benefit from using this calculator.

Industries that Can Use This Calculator

Retail, manufacturing, finance, healthcare, logistics, and any industry where accurate demand forecasting is crucial.

Benefits of Using This Calculator

  • Provides accurate forecasts for future demand.
  • Incorporates seasonality and trends into predictions.
  • Helps businesses optimize inventory management and resource allocation.
  • Enables informed decision-making based on reliable projections.


What is the significance of smoothing coefficients (α, β, γ)?

Smoothing coefficients determine the weightage given to recent observations versus historical data in the forecast calculations.

Can this calculator handle irregular data patterns?

Yes, triple exponential smoothing can adapt to irregular data patterns and adjust forecasts accordingly.


The Triple Exponential Smoothing Forecast Calculator allows businesses and individuals to make accurate predictions for future demand.  

By considering level, trend, and seasonality, it provides reliable forecasts essential for effective decision-making.