How To Calculate Seasonal Variation [exclusive] Jun 2026

"First," Leo said, "write down your total sales for each season for the last two years."

If the sum is 402 instead of 400, multiply each index by (400 / 402). Step 4: Deseasonalize Your Data how to calculate seasonal variation

A seasonal index of represents a perfectly average period. Anything above 1.0 is a peak , and anything below is a trough . If you'd like, I can help you further by: Providing a step-by-step Excel formula guide. "First," Leo said, "write down your total sales

| Month | Year 1 | Year 2 | Year 3 | | --- | --- | --- | --- | | Jan | 100 | 120 | 110 | | Feb | 90 | 100 | 105 | | Mar | 120 | 130 | 125 | | Apr | 110 | 120 | 115 | | May | 130 | 140 | 135 | | Jun | 140 | 150 | 145 | | Jul | 120 | 130 | 125 | | Aug | 110 | 120 | 115 | | Sep | 100 | 110 | 105 | | Oct | 120 | 130 | 125 | | Nov | 130 | 140 | 135 | | Dec | 150 | 160 | 155 | If you'd like, I can help you further

Since we have quarterly data, we use a to smooth out the seasonality.

Calculating seasonal variation helps you separate predictable cycles from general trends. Businesses use it to plan inventory, while economists use it to understand employment shifts. To find these patterns, you generally use the Ratio-to-Moving-Average method. Understand the Components