Demand Forecast Calculator

Forecast demand using moving average, weighted MA, and exponential smoothing.

Inputs

Month 1 Actual

Month 2 Actual

Month 3 Actual

Month 4 Actual

Month 5 Actual

Month 6 Actual

Smoothing Factor (alpha)

Tab to move between fields

Results

SMA Forecast (Next Month)

1,217

WMA Forecast1,233

Exponential Smoothing Forecast1,204

Trend-Based Forecast1,313

Monthly Trend (units)51.4

Monthly Growth Rate4.5%

Average Demand1,133

How to Use This Calculator

Enter actual demand for the last six months, from Month 1 (oldest) to Month 6 (most recent).
Set the smoothing factor (alpha, 0.01-1) — higher values give more weight to recent months in the exponential smoothing forecast.
Review the next-month forecasts calculated four ways: simple moving average, weighted moving average, exponential smoothing, and trend-based.
Check the monthly trend (slope) and monthly growth rate to see whether demand is rising or falling.
Compare the four forecasts alongside the average demand to gauge how closely the methods agree.

How the result changes with Month 6 Actual

Month 6 Actual	SMA Forecast (Next Month)
1,000,000	334,117
3,500,000	1,167,450
6,500,000	2,167,450
9,000,000	3,000,783

What each input means

Month 1 Actual: Actual demand for month 1 (oldest).
Month 2 Actual: Actual demand for month 2.
Month 3 Actual: Actual demand for month 3.
Month 4 Actual: Actual demand for month 4.
Month 5 Actual: Actual demand for month 5.
Month 6 Actual: Actual demand for month 6 (most recent).
Smoothing Factor (alpha): Exponential smoothing alpha (0-1, higher = more weight on recent).

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Month 1 Actual = 1000, Month 2 Actual = 1100, Month 3 Actual = 1050, Month 4 Actual = 1200 = 7 input(s) provided
Calculate SMA Forecast
1217 = 1217
Calculate WMA Forecast
1233 = 1233
Calculate Exponential Smoothing Forecast
1204 = 1204

Engine last updated August 6, 2026. Checked against 1 independently-derived test — how we verify calculators.

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