How To Calculate Seasonal Variation -

"Exactly. That's the 'flat line'—what you'd sell per season if there were no seasons at all." "Now for the magic," Leo said. "For each season, divide its average by the overall average. That gives you the Seasonal Index ."

Elena pulled up her tablet. She wrote:

"I know," Elena sighed. "But the seasons aren't the same every year. Last June was cold, but the June before that was a heatwave. How can I predict anything?" how to calculate seasonal variation

| Year | Season | Sales (USD) | | :--- | :--- | :--- | | Year 1 | Summer | $60,000 | | Year 1 | Fall | $20,000 | | Year 1 | Winter | $10,000 | | Year 1 | Spring | $30,000 | | Year 2 | Summer | $70,000 | | Year 2 | Fall | $25,000 | | Year 2 | Winter | $12,000 | | Year 2 | Spring | $35,000 | "Exactly

"That’s my overall average per season," she said. That gives you the Seasonal Index

Elena calculated: Last year's total = $70k + $25k + $12k + $35k = $142,000. Plus 10% growth = $142,000 × 1.10 = total for next year.