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Demand Forecast & Seasonality

Forecast demand with seasonality adjustments and promotional uplift modeling. Enter values for instant results with step-by-step formulas.

Worked Examples

Example 1: Holiday Sale

Problem:Base 1000, 1.5 Seasonality (Dec), 50% Promo Lift

Solution:Seasonal Base: 1500. Promo: 1500 * 1.5 = 2250.

Result:2250 Forecasted Units

Example 2: Summer Slump

Problem:Base 1000, 0.8 Seasonality (Aug), 0% Promo

Solution:Seasonal Base: 1000 * 0.8 = 800.

Result:800 Forecasted Units

Frequently Asked Questions

What is Seasonality?

Predictable, recurring fluctuations in demand (e.g., Ice cream in summer, Toys in December). It is usually expressed as an index (1.0 = average, 1.2 = 20% above average).

Why forecast decomposition?

It helps you know *why* sales happened. Was it the ad campaign? Or just Christmas? If you confuse Seasonality with Promo Lift, you'll overspend on ads.

How do I forecast revenue?

Bottom-up forecasting multiplies expected units sold by price. Top-down starts with market size and estimates market share. For existing businesses, use historical growth rates with adjustments. For SaaS: Forecast MRR = Current MRR + New MRR - Churned MRR + Expansion MRR. Always model best, expected, and worst case scenarios.