What's the simplest and easiest way of verifying the existence of seasonality on Excel?

Please recommended a method other than a time series plot/graph.

I have to check if Seasonality exists for 400+ products and drawing a time series graph for each one is going to be a pain in the neck. I was hoping for a formula-ish method which gives me a number that tells me whether seasonality exists or not.

Once seasonality is detected in the data of one SKU, I will run the Holt Winter's Method on it.

datascience excel seasonality